[HN Gopher] NASA's Perseverance rover sends stunning images
       ___________________________________________________________________
        
       NASA's Perseverance rover sends stunning images
        
       Author : astdb
       Score  : 929 points
       Date   : 2021-03-03 02:09 UTC (20 hours ago)
        
 (HTM) web link (www.bbc.com)
 (TXT) w3m dump (www.bbc.com)
        
       | malwarebytess wrote:
       | Stunning? Boring is the truth. They look as haphazard and
       | unconsidered shots of earthly, unremarkable, landscape.
       | 
       | NASA needs artists and poetic photographers to capture
       | inspiration on Mars if they want to snare the hearts of the
       | public. What a waste of fortunes if they cannot do that.
       | 
       | If only the images were as great as the feat and engineering
       | itself.
        
         | kgrimes2 wrote:
         | Dude, it's a scientific experiment, not a fucking Instagram
         | shoot
        
           | malwarebytess wrote:
           | That's not what this is. I didn't impugn the project did I? I
           | criticized the public relations blitz and a falsely
           | descriptive title on the BBC. Don't pretend public outreach
           | isn't part of the plan here.
        
             | kgrimes2 wrote:
             | What qualifies as "stunning" in your book if not photos of
             | another world?
        
           | bregma wrote:
           | Mars exploration is first and foremost a human experience.
           | Dry observation and engineering wet dreams are OK for a few
           | elite but what we're looking at here is a legacy for all
           | humankind. It should be treated that way, and that includes
           | emotional interpretations.
        
       | ForHackernews wrote:
       | The bottom of this page says: "All images copyright Nasa/JPL-
       | Caltech"
       | 
       | But I thought all works created by the US federal government are
       | public domain and not protected by copyright?
       | 
       | Famously the "Blue Marble" photo is not under copyright and
       | reproduced all over the place:
       | https://en.wikipedia.org/wiki/The_Blue_Marble
        
         | Denvercoder9 wrote:
         | That's probably just a mistake from the BBC. The original
         | source [1] just says "image credit" NASA/JPL-Caltech, not
         | copyright.
         | 
         | [1] https://mars.nasa.gov/mars2020/multimedia/raw-images/
        
           | WarOnPrivacy wrote:
           | I've come to expect news/media copyright mistakes to fail on
           | the side of copyright interests - and not the public's.
        
       | miguelmota wrote:
       | If anyone is curious about the technology powering the
       | Perseverance rover, there's this great video on YouTube
       | explaining the incredible engineering behind it:
       | 
       | https://www.youtube.com/watch?v=yqqaW8DCc-I
        
       | whatever1 wrote:
       | Anyone has insights on how data in such volumes can be
       | transferred from Mars to Earth in the absence of a direct link?
       | Do the intermediate nodes have gigabytes of available storage to
       | emit data to the next available node once it becomes visible ?
        
         | mmcconnell1618 wrote:
         | Vint Cerf has been working with NASA for over a decade on a
         | design for interplanetary internet. I work at Google and he
         | shared a story about how the earlier rovers had radios that
         | were overheating at higher bandwidth transmissions. A smart
         | engineer noted that they had an X band radio on the rover and
         | still had one in an orbiter around Mars. The rover could
         | transmit at 128mbps over xband to the orbitter, which in turn
         | had large antennas to transmit back to earth at 128mbps. I
         | assume Perseverance supports more bandwidth but it may be
         | limited by whatever equipment we have in orbit around Mars.
         | 
         | https://www.quantamagazine.org/vint-cerfs-plan-for-building-...
        
         | dekhn wrote:
         | See https://www.quantamagazine.org/vint-cerfs-plan-for-
         | building-an-internet-in-space-20201021/ for some details on
         | projects related to this. IIRC it's store and forward.
        
         | electriclove wrote:
         | Perseverance sends the data to various orbiters (satellites
         | already in orbit around Mars) during overflights (time windows
         | when the orbiter is in range of the rover) and those orbiters
         | then send (relay) the data to Earth via the Deep Space Network
         | (satellite dishes on Earth).
        
         | raynr wrote:
         | From my layman's understanding, it's relayed via the orbiters.
         | 
         | There are a few orbiters around Mars. NASA appears to have an
         | arrangement with the ESA to upload data from the rovers to the
         | ESA's orbiters, depending on whose orbiters are within line of
         | sight at any given time. Then the orbiter sends the information
         | back to Earth, which are received by NASA's Deep Space Network
         | 
         | During the time when line of sight between Earth and Mars is
         | blocked by Sol, there isn't any communication.
         | 
         | May interest you:
         | https://mars.nasa.gov/mars2020/spacecraft/rover/communicatio...
        
           | SturgeonsLaw wrote:
           | It never ceases to impress me that we have the ability to do
           | this sort of stuff. A couple thousand years ago, the height
           | of technology was shooting something from a few hundred
           | metres away with a bow and arrow, now we are landing machines
           | on another planet and transmitting data back and forth
           | through the solar system. Incredible.
        
             | mattmanser wrote:
             | A couple of thousand years ago is the peak of the Romans,
             | so you're way off on your 'height' of technology at that
             | time.
             | 
             | Using bows and arrows as an example when you've got wonders
             | of pretty advanced engineering like the Parthenon, plus
             | they also had ballistae, chariots and catapults, so not the
             | peak at all.
             | 
             | Not only that, but even the bows were more advanced,
             | composite bows much more powerful than simple ones made of
             | wood.
        
               | [deleted]
        
               | bloak wrote:
               | The most complex machine of the Roman era was perhaps a
               | water organ. (I would guess that for long historical
               | periods the most complex machines were keyboard-
               | controlled musical instruments.)
        
               | WarOnPrivacy wrote:
               | Oh see you did it now - opened up a vacuum about ancient
               | tech.
               | 
               | I'll start: https://en.wikipedia.org/wiki/Aeolipile
        
               | Bluestein wrote:
               | (The question as to how - and why or why not - we could
               | go from the Aeolipile to full blown steam engines, I've
               | always found fascinating ...
               | 
               | ... what other things / proceses / materials / frame of
               | mind made the steam engine possible vs. this.
               | 
               | What made for an industrial revolution in the 1800's vs.
               | the 1st century AD).-
        
               | rmu09 wrote:
               | One thing that severly hampered the romans was their
               | number system.
        
               | Bluestein wrote:
               | Makes sense that it would ...
        
               | mstade wrote:
               | Great link, thanks for sharing! This has the makings of
               | an excellent thread - please do continue sharing cool
               | stuff!! :o)
        
             | vkou wrote:
             | A couple of thousand years ago, humans built massive
             | engineering projects, including the Pyramids, massive
             | irrigation and earthwork systems, and tunnels, and bridges,
             | domesticated wild animals, produced metals - including
             | steel - out nothing but wood, water, and low grade ore,
             | etc, etc.
             | 
             | They did not have internal combustion engines, or
             | electricity, or the ability to machine parts to high
             | tolerances, but ancient engineers cared deeply about
             | efficiently transforming mechanical energy from one form to
             | another.
        
             | dvfjsdhgfv wrote:
             | Incredible for me, too. The power of building the
             | civilization, one generation after another, and of working
             | together, sharing the knowledge.
        
               | DrBazza wrote:
               | But according to Ancient Aliens, the large stone Pyramids
               | were built by aliens, but the TV cameras recording the
               | show's hosts, with CCDs, and likely 10nm chips inside,
               | were built by humans.
               | 
               | In all seriousness, it's impressive what knowledge
               | sharing and cooperation achieves.
        
               | dylan604 wrote:
               | It is highly unlikely that the cameras being used to
               | produce Ancient Aliens are CCDs unless they are also
               | using ancient camera tech. Most likely, the camera's
               | image sensors are CMOS. 3 chip CCDs reached their
               | pinnacle as 90s/early 00s tech. CCDs can only sense one
               | color, so they put three of them behind an RGB splitter.
        
               | zimpenfish wrote:
               | [Ancient Aliens] Ah but the cameras and chips are only
               | possible -because- the aliens built the pyramids and
               | inspired humans technologically and a mere 4450 years
               | later, voila! CCDs and computer chips!
        
               | dvfjsdhgfv wrote:
               | Well, given the fact that we still know relatively little
               | about most of the observable universe (dark matter &
               | energy), I don't think you can completely rule out the
               | several unlikely hypotheses. For example, that earlier
               | civilizations instead of electricity used a completely
               | different form of energy - and that basically directed
               | their development into a completely different direction,
               | not leaving many material artefacts. I don't believe this
               | actually happened, but a part of me knows that I can't be
               | 100% sure it didn't.
        
         | pkaye wrote:
         | They added dedicated storage in the rover itself to store phots
         | and videos. So for example they can compress the video files
         | before transmitting. I've hear they use ffmpeg for this
         | purpose. There are 4 orbiting satellites that can relay any
         | data sent to it.
        
         | akg_67 wrote:
         | Reddit had AMA with engineers from this mission, IIRC last
         | week. They provided good info on different aspects including
         | how they were able to get video over low bandwith connection,
         | including various mission site link for more info. You might
         | want to check out AMA for your question.
         | 
         | Edit: added following links
         | 
         | This Q&A about storage
         | https://www.reddit.com/r/IAmA/comments/lpzbzo/were_scientist...
         | 
         | These Q&A about data rate
         | https://www.reddit.com/r/IAmA/comments/lpzbzo/were_scientist...
         | 
         | https://www.reddit.com/r/IAmA/comments/lpzbzo/were_scientist...
         | 
         | This Q&A about RTG (operational life)
         | https://www.reddit.com/r/IAmA/comments/lpzbzo/were_scientist...
        
           | asaddhamani wrote:
           | Do you have a link to this AMA?
        
             | kgrimes2 wrote:
             | https://www.reddit.com/r/IAmA/comments/lpzbzo/were_scientis
             | t...
        
           | eCa wrote:
           | https://old.reddit.com/r/IAmA/comments/lpzbzo/were_scientist.
           | ..
        
           | jdmichal wrote:
           | Others have posted links to the Reddit thread overall, but I
           | think this is the specific question being referred to:
           | 
           | https://old.reddit.com/r/IAmA/comments/lpzbzo/were_scientist.
           | ..
           | 
           | EDIT: Apparently the rover has an antenna that can directly
           | communicate with Earth at 10 bits per second! That's
           | obviously not useful for pictures or anything, but it's an
           | amazing capability for emergency comms.
        
             | londons_explore wrote:
             | Very low bandwidth, very low power, very long distance
             | comms are really cool. The limiting factor tends to be the
             | clock frequency precision - if you have precise enough
             | clocks at both ends, there isn't anywhere in the universe
             | you couldn't communicate with, as long as you're happy to
             | go slow enough.
        
               | comboy wrote:
               | > there isn't anywhere in the universe you couldn't
               | communicate with
               | 
               | Right, assuming you are emitting infinite amount of
               | photons, there are no obstructions, black holes and you
               | ignore universe expansion and GR which can make your
               | precise enough clocks go out of sync.
        
               | UnFleshedOne wrote:
               | "Precise enough clocks" includes handling GR and other
               | non-destructive effects along the whole light path I
               | assume. :)
        
               | Bluestein wrote:
               | That's one big ask :)
        
               | [deleted]
        
               | londons_explore wrote:
               | > emitting infinite amount of photons
               | 
               | I think that the double slit experiment shows that this
               | isn't an issue... Since we are summing with all other
               | noise in the universe, it doesn't matter exactly _which_
               | photons came from my transmitter, if any at all, but the
               | total count will still (probabilistically) reflect the
               | the we 're after...
        
               | magicalhippo wrote:
               | Given self-clocking signalling[1] exists, why is clock
               | frequency precision the limiting factor?
               | 
               | I would imagine signal-to-noise would be the limiting
               | factor, ie how strong is your transmitter and how
               | sensitive is your receiver.
               | 
               | [1]: https://en.wikipedia.org/wiki/Self-clocking_signal
        
               | tremon wrote:
               | Noise, by definition, doesn't have a qualifying
               | characteristic. It just means "all signals we're not
               | interested in". That means your ability to filter out
               | noise is strongly dependent on having pre-existing
               | knowledge about the shape of the signal you're interested
               | in.
               | 
               | Self-clocking signals are useful when the ambient noise
               | level is low with respect to the signal, but if your
               | signal is just "these two droplets in an ocean" you will
               | not be able to filter out enough of the signal to detect
               | the edges of the original signal.
               | 
               | Having a very reliable clock frequency means you can
               | apply a very exact filter to lock on to the signal you
               | want, thereby making the transmission less sensitive to
               | interference from other radio signals. Just having a
               | sensitive receiver isn't enough, because a sensitive
               | receiver will also pick up more of the other radio
               | signals.
        
               | magicalhippo wrote:
               | Wrong clock, gotcha. For some reason I didn't think of
               | the carrier signal generator when I read the word
               | "clock".
               | 
               | It all makes sense now, thanks!
        
               | londons_explore wrote:
               | It is possible to send a signal _weaker_ than the noise
               | floor. The maximum information you can send is defined by
               | shannon 's channel capacity formula, which clearly says a
               | signal can be weaker than the noise.
               | 
               | If you use a self-clocking signal, then effectively the
               | information you are sending consists of both the clock
               | timings _and_ the information you 're really trying to
               | send. If your channel capacity is very low, you will find
               | there is no channel capacity for even the clocking
               | information, let alone the information you really want to
               | send.
        
       | billfruit wrote:
       | Any sound clips released as of now? I heard they had a microphone
       | on board unlike so many of the probes till now.
        
         | daverobbins1 wrote:
         | https://mars.nasa.gov/mars2020/participate/sounds/
        
           | billfruit wrote:
           | Actually they sound some what underwhelming.
        
       | WarOnPrivacy wrote:
       | Wholly cow. In that 2nd photo, the rover looks like it just
       | missed landing on a ridgeline.
       | 
       | ref:https://ichef.bbci.co.uk/news/976/cpsprodpb/58BB/production/.
       | ..
        
         | hyyypr wrote:
         | iirc the "landing crane" was doing autonomous live analysis of
         | the terrain and making the necessary last minute adjustments to
         | avoid problematic areas.
        
           | kesava wrote:
           | It was actually the rover itself doing those calculations
           | with it's set of radars and controlling the sky crane thru
           | the umbilical cords.
        
       | NoOneNew wrote:
       | Up to date image collection on the nasa site for anyone that
       | cares: https://mars.nasa.gov/mars2020/multimedia/raw-images/
        
         | ASalazarMX wrote:
         | We're seeing Martian robot selfies. Neat.
        
       | lovezone wrote:
       | Nice
        
       | DorianSinDeep wrote:
       | I think people who don't care for long term investments like this
       | are afraid of the idea that the world will go on without them
       | just as well as it is now. They believe in their fear that some
       | catastrophy bigger than their own death must be coming or what
       | was the point of their life at all? The world was fine before you
       | and it will be fine after you. Endeavours like these are the only
       | worthwhile contributions we have to make towards the future.
        
         | michelb wrote:
         | I think most people who are not a fan of space programmes would
         | like to have spent that money/effort on humanitarian and socio-
         | economic problems first. I say why not both? Just reduce
         | military spending.
        
       | asasidh wrote:
       | "The Perseverance rover has initial funding to operate for one
       | Mars year, roughly two Earth years."
       | 
       | So wire the rover money after 2 years ? no wonder Elon is into
       | Bitcoin
        
       | mojomark wrote:
       | What are the "dark spot anomalies" that appear to be floating in
       | the air in some images (1, 2)? Dust on the camera lens? I've
       | never looked at any rover images so I assume someone knows.
       | 
       | Also, whay are the images fairly low resolution compared to a
       | phones camera. Does it have to do with image data transmission
       | error?
       | 
       | Finally (then I'll shut up), when do we get to see the stereo
       | images? I want to see these on my Vive.
       | 
       | 1.) https://mars.nasa.gov/mars2020/multimedia/raw-
       | images/NLE_000...
       | 
       | 2.) https://mars.nasa.gov/mars2020/multimedia/raw-
       | images/SI0_001...
        
         | intrasight wrote:
         | Same question. Where are the stereo images?
        
         | maaaaattttt wrote:
         | My wild guess would be dust on the lens. Quickly looking at
         | related images shows black spots present at the same locations
         | relatively to the image's frame.
        
       | berkes wrote:
       | Looking at closeups of the Rover, I cannot help but think: are
       | those screws, nuts and bolts? And if so, why? Why carry the
       | weight or decreased stiffness of or by the notches, slits,
       | threads etc. that makes screws be screwable. To a place where no-
       | one ever will unscrew them?
        
         | carabiner wrote:
         | Because you'd need higher weight in wall thicknesses if using
         | weaker 3D printed aluminum instead of aluminum sheet, bar stock
         | etc. Which actually has a coherent grain.
        
         | vasco wrote:
         | I predict that the chances of someone ever unscrewing them are
         | higher than not. Just not super soon.
         | 
         | Plus during development its useful, and why would you change
         | the platform you test when deploying to live?
        
           | berkes wrote:
           | My thoughts as well: the benefits during development outweigh
           | any downsides during transport and deployment.
           | 
           | My other thought is that I simply saw it wrong and there are
           | no screws in the rover, just things that look like screws,
           | nuts or bolts.
        
           | bregma wrote:
           | The chances of someone unscrewing on Mars are a million to
           | one they said.
        
         | johnchristopher wrote:
         | I'd be amazed if we could build a single-use unibody rover but
         | even so I suppose those bolts and nuts give some needed
         | flexibility when landing and moving.
         | 
         | Any structural engineer around?
        
       | teleforce wrote:
       | This is a video presenting ten milestone images that revealed
       | what we've learned about Mars after decades of exploration prior
       | to the landing of Perseverance [1]. It's nice to see the
       | evolution of image resolutions of the Red Planet.
       | 
       | [1]https://www.youtube.com/watch?v=e1eFMzO3iPc
        
         | dredmorbius wrote:
         | Similar, a gf capturing the evolution of our knowledge of Puto
         | in somewhat less than a century:
         | https://i0.wp.com/www.nasa.gov/sites/default/files/styles/fu...
        
           | TeMPOraL wrote:
           | Great. Sometimes it feels like there's little progress made
           | in space exploration. But such a compilation is a good
           | reminder that - yes, maybe it's a bit too slow for the
           | impatient, but progress is being made, and it shows.
        
             | dredmorbius wrote:
             | That period during the New Horizons mission where _every
             | new image_ represented a major advance in our quantum of
             | knowledge of Pluto was absolutely remarkable.
             | 
             | The situation with Mars is different: the planet's close
             | enough for reasonably good telescopic investigation from
             | Earth, we've had landers on the planet for 50 years (the
             | Soviet Mars 2 lander beat Viking by 5 years), high-
             | resolution orbiters for ... nearly as long? And since 1996,
             | rovers, which have transected paths of varying lengths
             | exploring specific regions of the plant. We've got a very
             | strong overview (something still not complete for Pluto ---
             | New Horizons got detailed close views of only about 60% of
             | the surface), and several very-high-detail pictures.
             | 
             | Astronomical time and distance are both huge relative to
             | human scale. That we (or our robot agents) can cross the
             | solar system in a decade or two is remarkable. A few months
             | to Mars is nothing. The Earth was once as large or far
             | larger (to us).
        
       | throwaway888abc wrote:
       | The photos are stunning!
       | 
       | Scratching head why one would like to live on Mars ?
        
       | snicker7 wrote:
       | Any good desktop wallpapers out of this?
        
         | 29athrowaway wrote:
         | Curiosity took pretty nice pictures that you can very easily
         | turn into wallpapers.
         | 
         | https://mars.nasa.gov/resources/curiositys-1-8-billion-pixel...
         | 
         | Take the second one from that page, for instance, zoom in, and
         | just take a screenshot and use it as your wallpaper.
        
       | nsturtz wrote:
       | That is so cool :)
        
       | itbeho wrote:
       | "And we made it to Mars! I stepped out of the lander and took a
       | look around. It turns out the place is just a bunch of rusty
       | looking rocks. No hot green chicks, no angry little green men. I
       | guess I was kind of hoping there would have been someone here to
       | shoot it out with, or at least make out with."
       | 
       |  _- From the unpublished short fiction of itbeho_
       | 
       | Seriously though, this is fantastic. Imagine being a kid today,
       | seeing these images and being inspired to help get us there in
       | person, hopefully in the near future.
        
         | novaRom wrote:
         | Are you serious? First Vikings landed there 50 years ago. Kids
         | of 70th and 80th did seeing first images, there were many
         | colorful books about solar system. It's pitty how badly slow is
         | space exploration of last decades. No wonder everyone and its
         | dog are now so excited about this mission.
        
       | jerkstate wrote:
       | I remember a recent article on HN about being able to receive
       | signals from Tianwen-1 with a homemade satellite dish - is it
       | possible to receive these pictures over radio with the right
       | equipment, or do they come down encrypted?
        
         | azernik wrote:
         | Data comes from Perseverance through two channels:
         | 
         | * A low-bandwidth direct link to Earth (160bps-800bps depending
         | on receiver dish- no, that's not a typo)
         | 
         | * A high-bandwidth link to orbiting satellites, which then
         | forward traffic to Earth (~2Mbps for the rover->orbit hop,
         | anywhere from 0.5-4Mbps for the orbit->Earth) .
         | 
         | I strongly suspect that the low-bandwidth telemetry signals -
         | equivalent to the homemade reception from satellites I've heard
         | of - are sent in the clear. Bandwidth is just too precious to
         | waste.
         | 
         | I would not be surprised either way for the image data - on the
         | one hand, computing power is relatively scarce, while on the
         | other hand it already has to go through a compression pipeline.
         | 
         | https://mars.nasa.gov/msl/spacecraft/rover/communication/
        
         | ddevault wrote:
         | If I recall correctly, the Tianwen-1 amateur signal reception
         | was (1) shortly after launch, and (2) using a 20 meter dish.
         | Receiving the downlink from a deep space object requires much
         | more sophisticated technology than most amateurs have access
         | to, both to track the object, and to listen hard enough.
         | 
         | That being said, I doubt that the transmissions are encrypted.
         | Hell, I bet some amateurs with a very powerful transmitter
         | might be able to transmit a software update and take control of
         | the rover.
         | 
         | https://xkcd.com/1337/
        
         | soheil wrote:
         | I would think encryption would slow down the transmission rate.
         | So most likely are sent in the clear
        
           | hackeraccount wrote:
           | I'm not saying they are encrypted but I thought that
           | encryption is a close cousin to compression - that it
           | generally doesn't add overhead.
        
       | snickms wrote:
       | This mission is an incredible achievement. The images are as
       | advertised (stunning) and I'm sure all the sciences - and even
       | art - will benefit from the data.
       | 
       | What I find a little sad is that we seem incapable of doing this
       | without leaving a particularly human signature wherever we go.
       | 
       | We arrived on Mars with jets of pollution
       | https://mars.nasa.gov/resources/25672/black-and-white-smoke-...
       | followed by the dumping of the two pieces of trash required to
       | enable the landing.
       | 
       | For all the data we have gained, we have lost a pristine planet -
       | which makes me wonder if we are doing this at the right time.
        
         | kbelder wrote:
         | We're disturbing all those pristine impact craters.
        
         | ozim wrote:
         | I have an opposite view of this.
         | 
         | Cosmos and Mars, Sun whatever else was there long before us an
         | will be still there long after us. From cosmic point of view
         | humanity does not matter much.
         | 
         | From that 1000ft view humans and whatever we built is natural
         | and not different than colony of ants. We are just sand grains
         | that will be crushed when next big asteroid comes by.
         | 
         | Having pristine planet like Mars has no value besides human
         | point of view "I want". Let alone planets are not pristine they
         | are bombarded with space trash like asteroids all the time :)
         | 
         | Why do we use such anthropocentric view? It makes any
         | difference if there is parachute on Mars? Pollution? Well we
         | defined pollution because it is something we want to get rid of
         | because it makes us sick. There is much more bad things for
         | humans in space than you can count.
        
           | snickms wrote:
           | What if in the future we could examine the contents of a
           | particular rock from space? Have instruments sensitive enough
           | to detect the remnants of Vogon breath from their visit
           | millions of years ago?
           | 
           | A pristine planet has value beyond 'I want this' IMO - it is
           | an opportunity to perform experiments in an almost perfectly
           | isolated test tube.
           | 
           | As a human, I also find it beautiful. As you say though, this
           | is an anthropocentric view.
        
         | bogwog wrote:
         | That "jets of pollution" is the equivalent of a fart in the
         | wind
        
       | endoelenar58 wrote:
       | Curious, whether rover survives to the return sample mission.
        
       | milofeynman wrote:
       | How close was the rover to its intended landing spot?
        
         | jcims wrote:
         | Nailed it - https://www.jpl.nasa.gov/images/avoiding-hazards-
         | at-jezero-c...
         | 
         | (A little more complicated than that of course. If I understand
         | correctly, anything in blue was a candidate landing spot that
         | it was free to select from. I'm pretty sure the header image is
         | an artistic crop :) )
        
           | sp332 wrote:
           | It was almost that good. It had a five-mile-wide ellipse to
           | search, and found a spot close to the middle. https://science
           | .sciencemag.org/content/sci/371/6532/870/F1.l... If you have
           | a Science magazine subscription, the image is from this
           | article: https://science.sciencemag.org/content/371/6532/870?
           | rss=1/sh...
        
         | Cogito wrote:
         | It landed quite close to the centre of its landing ellipse,
         | which was significantly smaller than the landing zones of
         | previous missions.
         | 
         | Perhaps most impressive is the success of the terrain relative
         | navigation. During descent a specific landing site was chosen,
         | after going through atmospheric entry. That site had to be
         | reachable based on where they ended up after entry, needed to
         | be safe to land in, and should land as close as reasonable to
         | scientifically interesting sites. The system chose a pixel from
         | the initial images taken during descent, and the final landing
         | was within 5m of that spot.
        
       | 11thEarlOfMar wrote:
       | Stupid question, but where is Perseverance's energy source?
       | 
       | Answer: Plutonium
       | 
       | It powers a Multi-Mission Radioisotope Thermoelectric Generator.
       | 
       | The plutonium decays at a few % per year, so that means it should
       | be able to bring Elon a sandwich when he lands.
       | 
       | https://mars.nasa.gov/mars2020/spacecraft/rover/electrical-p...
        
         | marshmallow_12 wrote:
         | a glowing green sandwich covered in red sand. But seriously,
         | this stuff is powering those voyager probes 40 years later.
         | Which makes me ask: why do we have to send there technologies
         | 10 billion miles away to make them work? Why can't my fridge be
         | powered this way?
        
           | neolog wrote:
           | I'd be interested in a real answer to this if any nuclear
           | engineers are around
        
             | ChuckMcM wrote:
             | Not a nuclear engineer, but we covered this in my third
             | semester of physics at University. The short answer is
             | there isn't any engineering reason why you can't do this.
             | The "real" reason is that there is liability here that
             | nobody knows how to deal with. If the unit became damaged
             | and its shielding failed it could sit there and kill people
             | who came near it for years (for example).
             | 
             | I got to talk to one of the engineers who worked on
             | KRUSTY[1] a 10kW nuclear reactor. This combined with some
             | batteries for peak load could run pretty much any house for
             | a couple of decades. (they talk about several houses in the
             | article but realistically the peak load of a single house
             | when the oven, refrigerator/freezer compressor, and central
             | AC are running is a bit north of 10kW. I would seriously
             | consider a way off grid ranch house if I could have one of
             | these to power it :-)
             | 
             | [1] https://www.popularmechanics.com/space/moon-
             | mars/a20127140/n...
        
               | ttul wrote:
               | Plus the 90kW of waste heat would keep you very warm.
        
               | ChuckMcM wrote:
               | So true, of course if I lived in a place where it snowed
               | I would put water pipes under the sidewalks and driveway
               | and recirculate water through them and a heat exchanger
               | near the reactor. Voila, no more shoveling snow!
        
             | burnte wrote:
             | RTGs get hot, that's the point of them, actually. Too hot
             | for use in a small area like your fridge. On a space probe
             | or rover on a cold planet, the waste heat is useful in
             | keeping things somewhat warm. On earth, not so much.
             | 
             | RTGs are also large, too large to power a fridge given the
             | power draw for a fridge. There were microRTGs used in some
             | pacemakers, but the long term safety concerns were never
             | overcome.
             | 
             | The decay rate is high enough that you'd need to augment or
             | refuel your house every handful of years. Halflife of 87
             | years, 25% energy loss in 40ish, 10% loss in just over a
             | decade, etc.
             | 
             | Also, they've got little plutonium pellets in them, which
             | is both expensive and dangerous.
        
               | oso2k wrote:
               | Many advocate for the use of Thorium instead.
        
           | matheusmoreira wrote:
           | Surely it would be a horrible idea to distribute radioactive
           | materials to the general population.
           | 
           | https://en.wikipedia.org/wiki/Goi%C3%A2nia_accident
        
           | King-Aaron wrote:
           | Aside from the high cost of a consumer grade plutonium RTG,
           | and the size constraint issues with putting one in the base
           | of a fridge, or the health risks with having a reactor in
           | your house under your food, one reason might be to prevent
           | people exploding them.
        
           | [deleted]
        
           | shkkmo wrote:
           | The 8 figure price tag for a RTG makes consumer use
           | uneconomical.
        
             | extrapickles wrote:
             | The reason for that high of a price tag is that the
             | engineering costs are spread over a very few units. If they
             | made 100,000 of them, the costs would be much closer to the
             | materials cost.
        
               | adrianN wrote:
               | So only six figures for fridge? Sounds like a good deal.
        
               | raverbashing wrote:
               | > the costs would be much closer to the materials cost
               | 
               | Which is? Not cheap. And it's not like you can buy in any
               | corner store.
               | 
               | And no, while an "economy of scale" would make it
               | cheaper, it doesn't mean it would be cheap.
        
               | extrapickles wrote:
               | I never said they would be affordable even in qty 100k.
               | 
               | I would think the major use for them beyond space probes
               | would be providing last resort backup power/heat for life
               | support on outside earth orbit space habitats/crewed
               | vehicles as the cost will still be at least $500/watt.
        
             | oso2k wrote:
             | More than likely, 99% of that cost is the container and the
             | apparatus to make use of its energy. [0][1]
             | 
             | [0] https://www.thoughtco.com/what-is-most-expensive-
             | element-606...).
             | 
             | [1] https://www.sciencedirect.com/topics/earth-and-
             | planetary-sci....
        
               | Balgair wrote:
               | Plutonium-238 can only be made via Uranium-238. Per the
               | Seaborg process, you must bombard U-238 with deuterons to
               | get Neptunium-238, which then further decays into Pu-238.
               | The Pu-238 then decays into U-234 with a half life of ~88
               | years. U-234 has a half life of ~200,000 years, btw.
               | 
               | It is _very unlikely_ that the production of Pu-238 would
               | cost less to produce than the container and the apparatus
               | that harvests the energy.
               | 
               | Let alone the issues with the waste products of U-234
               | hanging about in the kitchen or basement. If you think
               | climate change is bad as is, add in what people will do
               | when faced with surplus uranium waste removal costs.
               | 
               | https://en.wikipedia.org/wiki/Plutonium-238
        
           | mLuby wrote:
           | Back in the 60's, people thought everything would be nuclear-
           | powered; atomic cars, planes, trains, houses, etc. But like
           | with building-sized computers, we've chosen a different path
           | through the tech tree.
           | 
           | There were terrestrial exceptions though, like "the Beta-M is
           | a radioisotope thermoelectric generator (RTG) that was used
           | in Soviet-era lighthouses and beacons."
           | https://en.wikipedia.org/wiki/Beta-M
           | 
           | But people happened across them and got radiation poisoning,
           | so imagine that happening a lot more often if they were
           | powering all manner of home appliance. Also a lot more dirty
           | bombs.
        
           | idlewords wrote:
           | The Russians tried powering a bunch of remote stuff with
           | plutonium batteries during the Soviet era. It did not end
           | well, and cleaning those up has been an ordeal. Pu-238 was
           | also used in pacemakers. The basic problem is just that
           | plutonium is toxic as hell.
        
             | gambiting wrote:
             | I mean, US has been employing RTGs to power all kinds of
             | stuff too, it's not just Russians which did. But yes,
             | actually collecting and decommissioning them after the
             | collapse of the Soviet Union has been an ordeal.
        
             | bregma wrote:
             | More accurately, plutonium is as toxic as lead. It's also a
             | bit more radioactive than lead.
        
             | sgt wrote:
             | No no.. My grandfather from Irkutsk oblast had plutonium
             | heart, and he live to long ripe age of 45! Almost unheard
             | of in Soviet union.
        
             | baybal2 wrote:
             | Not plutonium, strontium
        
           | vharuck wrote:
           | Smoke detectors rely on a circuit powered by atomic fission
           | ionizing the air. It isn't their power source (they still
           | need batteries), but it is a safe way to get continuous
           | electricity.
           | 
           | https://www.nrc.gov/reading-rm/doc-collections/fact-
           | sheets/s...
           | 
           | There's probably a way to get a little more power out of it
           | without being too dangerous. But then we'd have ordinary
           | citizens buying things over-the-counter that could be abused
           | in bulk. And I don't see any hassle being worth an extra free
           | outlet or not replacing batteries.
        
           | AnimalMuppet wrote:
           | What's powering Voyager is a plutonium pile. Pretty sure you
           | don't want that in your fridge. 10 billion miles from me?
           | Sure, knock yourself out. 10 feet from me? _No way._
        
             | nitrogen wrote:
             | AKA "Not In My Back Yard."
             | 
             | So the question stands and extends to include this: "why
             | not?"
        
               | f-word wrote:
               | There's a TON of power generation alternatives that look
               | much better both from the "trying to not give you a lot
               | of cancer" standpoint _and_ the  "efficiency is something
               | we care about" standpoint. Most RTGs make about 3 to 6%
               | efficiency, while a random Amazon 100w solar panel will
               | give you 15/22% without most of the risks.
               | 
               | The main reason this are used vs (or sometimes along!)
               | other technologies is that they function rather happily
               | in super crappy conditions we don't -unless some world-
               | ending event happens soonish- usually have on Earth.
        
               | perardi wrote:
               | People are probably going to answer "safety".
               | 
               | But it's also hideously expensive. Plutonium is,
               | apparently, one of the safer ways to build these things,
               | because it is easy to shield, and the power density is
               | good. But plutonium, as it's not naturally occurring, is
               | stratospherically expensive.
               | 
               | https://en.wikipedia.org/wiki/Radioisotope_thermoelectric
               | _ge...
        
               | watersb wrote:
               | The first nuclear bombs cost billions of dollars each.
               | 
               | I wish I could say that's a good thing. But no, after the
               | first of them, nuclear weapons seem to have justified
               | their own existence, no matter the cost.
               | 
               | I would rather see remaining weapons material repurposed
               | as deep-space power sources. If that were to solve
               | problems.
               | 
               | Anyhow, Perseverance makes me happy.
        
               | Alghranokk wrote:
               | > I would rather see remaining weapons material
               | repurposed as deep-space power sources. If that were to
               | solve problems.
               | 
               | Unfortunately this is not possible, nuclear weapons make
               | use of pu-239, which has properties that does not make it
               | a useable RTG fuel.
        
               | baybal2 wrote:
               | > The first nuclear bombs cost billions of dollars each.
               | 
               | No, at least union's ones were priced at around
               | $100000-$120000 a pop in materials.
               | 
               | Giant amount of money back in seventies union for an
               | individual, enough to live on for a lifetime.
        
               | Balgair wrote:
               | Additionally, the decay product of Pu-238 is U-234.
               | Though a relatively 'safe' alpha emitter, it's half-life
               | is ~200,000 years.
               | 
               | Note: With alpha emitters, it's 'safe' if it's outside
               | your body, your skin can absorb it. But once you eat or
               | inhale it, you get the full blast right into the quickest
               | dividing cells in your body.
        
               | neuronic wrote:
               | To add to the other posts: nuclear weapons proliferation
        
               | rtkwe wrote:
               | There's a lot of waste heat put out by RTG. The one
               | powering Perseverance has an output of about 110W but
               | thermocouples have about 5% efficiency so there's ~1900W
               | of heat you have to deal with. For a fridge the running
               | power can be almost double that it's just completely
               | silly on Earth except for odd places like the lighthouses
               | along Russia's northern coast where there was no way to
               | get a grid connection, not enough sun for solar, and
               | suppling diesel constantly was impractical.
        
               | leijurv wrote:
               | Nuclear reactors are better and have economies of scale,
               | it doesn't make much sense to everyone have their own.
        
               | ddingus wrote:
               | Risk?
               | 
               | That is my basic opposition. Happy to be flexible on
               | energy in almost every way. Cost, type, uptime...
               | 
               | But error with nuclear tech tends to endure for a very
               | long time. Fukushima will be raising ocean radiation for
               | a long time, just one example.
               | 
               | These are many lifetime events. Some minor, or
               | recoverable, some profound.
               | 
               | Given we can reasonably run the fridge on solar, and
               | other tech, that risk does not seem to make sense to a
               | lot of people.
               | 
               | Doesn't to me.
               | 
               | Now, that said I am not ideologically opposed. Other tech
               | could very seriously improve risk profile. Maybe it
               | becomes worth it.
               | 
               | Then again, the fridge in my RV can run on a small flame,
               | or a very low current source. And no moving parts!
               | 
               | So, we could make fridges differently too. Make
               | tradeoffs.
        
               | antientropic wrote:
               | > Fukushima will be raising ocean radiation for a long
               | time, just one example.
               | 
               | Will it? The ocean is very, very big. Contaminated water
               | from Fukushima is a literal drop in a bucket.
        
             | ip26 wrote:
             | It's not actually a reactor. The plutonium is just emitting
             | radiation, as plutonium will do, and you harness some of
             | the natural heat energy with thermocouples. There's no
             | explosion risk, although you would certainly need
             | trustworthy shielding.
        
             | khuey wrote:
             | The radiation emitted by plutonium 238, which is what's
             | found inside RTGs, is easily shielded by essentially any
             | solid material.
             | 
             | The real reason you don't want an RTG powering your fridge
             | is that it costs on the order of one million dollars per
             | watt.
        
               | imhoguy wrote:
               | And recycling en masse would be nightmare. We got anough
               | hassle with R* gases.
        
               | waheoo wrote:
               | Economies of scale would surely change that though?
        
               | briga wrote:
               | Plutonium is fairly rare, so I'm not sure it could be
               | scaled up easily, even if there was a demand for it. Not
               | to mention we probably don't want the raw material for
               | nuclear bombs to be inside easily accessible home
               | appliances...
        
               | tachyonbeam wrote:
               | To some extent, but plutonium is relatively rare. Because
               | it's radioactive an it decays, there isn't that much in
               | nature. You can make some as a byproduct of uranium
               | fission reactors, but again, I believe collecting and
               | refining it takes a lot of energy... You could always
               | cover your roof in solar panels. They could potentially
               | last 40 years, and the cost is anywhere between 10K to
               | 20K installed. It's relatively affordable amortized over
               | a 30-year mortgage, and considering it produces usable
               | power.
        
               | rtkwe wrote:
               | Plutonium was generated in reactors in the US but those
               | were all shut down by the late 80s. It's not an easy
               | thing to just mine or make more of there were whole
               | reactors basically dedicated to just what we have left
               | today. In fact we're kind of running out of the stuff for
               | scientific missions, NASA only has enough for one RTG
               | left according to reports.
               | 
               | https://fas.org/sgp/othergov/doe/pu50yc.html
               | 
               | https://mjosefweber.medium.com/nasa-needs-plutonium-
               | ea3bbaad...
        
               | khuey wrote:
               | The situation for Pu-238 production has improved since
               | that was written https://www.ornl.gov/news/ornl-produced-
               | plutonium-238-help-p...
        
               | simcop2387 wrote:
               | Not really, it's all artificially produced and would
               | require generation of lots of power (it comes from
               | reactors) to produce it at scale. The only times we used
               | to do it at any reasonable scale was for nuclear weapons.
               | It's also restricted by treaty because of this.
        
               | 0xfaded wrote:
               | I was thinking it would be fun to buy some uranium 238
               | (you can have up to ~7kg of it without a license). Then I
               | tried ddg'ing what it would cost to dispose of. I
               | couldn't find an answer, so I decided buying uranium
               | wasn't a good idea.
               | 
               | It's hard enough getting rid of an old lead-cell battery.
        
               | lostlogin wrote:
               | I do wonder what it takes to end up on a watch list and
               | assumed attempting to get plutonium or even discussing an
               | attempt would be a guarantee.
               | 
               | I went searching and this website on watch lists appears
               | to be real, whilst also seeming like a joke.
               | 
               | "Since there are many reasons why a traveler may seek
               | redress, DHS TRIP works with the TSC, as appropriate,
               | when an inquiry appears to be related to the watchlist.
               | 
               | The TSC does not accept redress inquiries directly from
               | the public. Instead, members of the public should contact
               | the relevant screening agency with their questions or
               | concerns about screening."
               | 
               | https://www.fbi.gov/about/leadership-and-
               | structure/national-...
        
               | avereveard wrote:
               | They're also quite massive, and radiate a lot of waste
               | heat.
        
               | matheusmoreira wrote:
               | > easily shielded by essentially any solid material
               | 
               | If that shield fails for any reason, including tampering,
               | you're looking at the radiological contamination and
               | likely deaths of everyone nearby at the very least.
        
               | khuey wrote:
               | Alpha sources outside the human body are of little health
               | concern. You'd have to break it open and eat the
               | plutonium inside for it to be a serious risk.
        
               | matheusmoreira wrote:
               | > You'd have to break it open and eat the plutonium
               | inside for it to be a serious risk.
               | 
               | Yes. Sounds like something a child would do.
        
               | snet0 wrote:
               | Yes, just like how children regularly eat kitchen knives.
        
               | serf wrote:
               | aside from the fact that 'breaking open a refrigerator'
               | doesn't remotely sound like something a child would ever
               | do to me, let's assume the worst and the child somehow
               | opens up a refrigerator.
               | 
               | a conventional fridge has electric motors/pumps , live
               | a/c wiring, and gas under pressure. It's not radiation-
               | spilling-everywhere unsafe, but it's not really safe for
               | the kid, either.
        
               | matheusmoreira wrote:
               | That refrigerator is discarded. It ends up in a
               | scrapyard. Someone comes, sees the shielded capsule
               | containing radioactive material and harvests the lead.
               | The remains are eventually sold to someone else and it
               | ends up in that person's home where children are likely
               | to become fascinated by it or even eat it.
               | 
               | Everyone who went near this thing is likely to become ill
               | _at the very least_.
        
               | adrianN wrote:
               | Plutonium dust is very dangerous and you don't want to be
               | around the decay products either. Plutonium also likes to
               | catch fire.
        
               | scoopertrooper wrote:
               | How familiar are you with the human species? There have
               | been several notable accidents where humans have cracked
               | open medical machines and decay powered lighthouses to
               | exactly this effect. Imagine if you started whacking
               | plutonium in consumer products!
        
               | M2Ys4U wrote:
               | > How familiar are you with the human species? There have
               | been several notable accidents where humans have cracked
               | open medical machines and decay powered lighthouses to
               | exactly this effect. Imagine if you started whacking
               | plutonium in consumer products!
               | 
               | People already dope silicone bands and fabric (including
               | underwear!) with Thorium and sell them as "negative ion"
               | "wellness" products. Some are still available to buy on
               | Amazon.
               | 
               | Because there's nothing like "wellness" than exposing
               | your gonads to ionising radiation!
        
               | matheusmoreira wrote:
               | > There have been several notable accidents where humans
               | have cracked open medical machines and decay powered
               | lighthouses
               | 
               | Indeed.
               | 
               | https://en.wikipedia.org/wiki/Goi%C3%A2nia_accident
               | 
               | A caesium-137 radioactivity source was left behind and
               | eventually stolen. The thieves successfully dismantled it
               | despite sustaining severe injuries in the process,
               | exposing the radioactive material contained in the
               | shielded capsule. They were fascinated by the strange
               | light emitted by it.
               | 
               | Eventually it was sold to a scrapyard. The owner also
               | became fascinated with the blue glow. He brought the
               | thing home to show everyone. He distributed parts of the
               | material to friends and family. Eventually sold it to
               | another scrapyard but not before his brother took some of
               | the beautiful radioactive dust and smeared it on the
               | concrete floor. Where his daughter sat and ate a
               | contaminated sandwich. She also applied he powder on her
               | own body.
               | 
               | The only reason this unfortunate chain of events stopped
               | is the scrapyard owner's wife noticed everyone was
               | getting sick and notified the authorities. She died later
               | along with the girl. Attempts to bury the child also led
               | to a riot. Scrapyard workers also died attempting to
               | extract the lead from the radiation shielding component.
        
               | avar wrote:
               | > the scrapyard owner's wife noticed everyone was getting
               | sick and notified the authorities[...]
               | 
               | The Wikipedia article and the Portuguese source it links
               | to seems ambiguous on the matter of whether it was
               | because she notified the authorities, or because a
               | visiting scientist thought to use radiation detectors on
               | other people reporting to the hospital a day after her
               | notification.
        
               | no-s wrote:
               | let's not forget that nation-state(s) (maybe singular,
               | but not certain) have weaponized Polonium[1], and also
               | the ubiquity of americium-241[2] which could be used
               | similarly...Outside the human body but readily available
               | for inimical ends...
               | 
               | [1] https://en.wikipedia.org/wiki/Alexander_Litvinenko
               | [2] https://en.wikipedia.org/wiki/Smoke_detector
        
               | fnord77 wrote:
               | or breathe particles. grind it up into a fine powder and
               | you have a nasty dirty bomb
        
               | rapsey wrote:
               | That plutonium would end up in scrap heaps. Cointainers
               | would break open and people would pretty much spread it
               | everywhere from there.
        
               | yread wrote:
               | Plutonium is also highly (chemically) toxic.
        
           | jb775 wrote:
           | Because if you can power a fridge this way, you can power an
           | automobile this way. They won't let this happen.
           | 
           | The current power structures in the world (petrodollar, etc)
           | and world economy as a whole (massive employment within oil
           | industry and throughout supply chains catering to oil
           | industry) are too intertwined with the oil industry to allow
           | _any_ other technologies to swiftly disrupt that.
        
           | ryandvm wrote:
           | Are you really asking why we can't power your fridge with
           | plutonium?
        
             | junon wrote:
             | Do you have an answer that isn't speculation or something
             | you concluded from a breezy stroll over to Wikipedia?
             | 
             | Stop mocking questions. It solves nothing.
        
               | ryandvm wrote:
               | Fair enough. I probably should have dialed down the
               | snark.
               | 
               | I suppose if we're looking for a Randall Munroe / "What
               | If?" style explanation of why powering consumer equipment
               | with plutonium is a bad idea, then it was the right
               | question to ask.
        
               | btilly wrote:
               | Each Mars Rover uses 5 kilograms of plutonium 238.
               | (Plutonium 239 is the one that is used in nuclear bombs.)
               | 
               | Per https://www.wired.com/story/nasas-mars-rover-will-be-
               | powered... we currently have a lab dedicated to producing
               | it, and it makes 3.5 pounds per year.
               | 
               | Per https://www.npr.org/2011/11/08/141931325/the-
               | plutonium-probl... the cost of getting the lab restarted
               | was a bit shy of $100 million. And once running fully it
               | costs millions of dollars to run.
               | 
               | At those cost points it would be cheaper to deliver you a
               | brand new fridge each month for the next 20 years than to
               | deliver you a single fridge using plutonium to run
               | without external electricity for the same 20 years. Not
               | to mention that the plutonium itself is toxic.
        
               | junon wrote:
               | Thanks for the info, interesting.
               | 
               | Though FWIW I was more commenting on the mocking of a
               | legitimate question. Not everyone has the same background
               | as everyone else. There are no stupid questions.
        
             | newsbinator wrote:
             | I come to HN because yes, people are really asking and
             | really answering. It's currently the best forum on the
             | internet for this reason.
        
             | mzg wrote:
             | Not sure about you, but I was promised fusion-powered
             | DeLoreans by now.
        
               | justinator wrote:
               | You don't have the Mr. Fusion upgrade? Run that sucker on
               | trash. Had it since 2015.
        
               | ryandrake wrote:
               | I was promised that by at least 1985, plutonium would be
               | available in every corner drugstore.
        
           | oconnor663 wrote:
           | You know I was about to say something about how your fridge
           | draws so much more power than these probes, but actually I
           | just googled it and they're pretty close. Today I learned.
           | 
           | (I don't know how much power the probes actually _use_ , but
           | anyway the wattage of the RTG itself is pretty close to the
           | steady state power consumption of a fridge.)
        
           | Johnny555 wrote:
           | _Why can 't my fridge be powered this way_
           | 
           | The MMRTG is a cylinder 25" in diameter and 26" high, it's
           | going to seriously impact space in your 'fridge. Plus it
           | weighs nearly 100 lbs.
           | 
           | It outputs around 100W of power, which might be enough for a
           | small refrigerator, but it also emits around 2000W of thermal
           | energy, so your kitchen's going to get a little warm
           | (probably a good thing in the winter, not so much in summer).
           | 
           | Though probably the biggest drawback is the cost -- the MMRTG
           | costs around $100M to manufacture. The US Department of
           | Energy makes the plutonium for it.
        
             | m4rtink wrote:
             | There are more efficient Stirling Engine based RTGs in
             | prototype phase that would be a much better fit for your
             | fridge as they could run the compressor directly. And also
             | add a nice nuclear-steampunk flair to the whole thing. :)
        
             | TeMPOraL wrote:
             | And, if you somehow manage to procure one to power your
             | fridge _and_ complete all the necessary paperwork for it to
             | be legal, you 'll be on the radar of pretty much every
             | single three and four-letter agency in your country.
             | 
             | Not just the obvious ones (checking if you aren't selling
             | plutonium or making a dirty bomb), but also health agencies
             | (what if it leaks and someone eats it?), environmental
             | agencies (what if it leaks and gets into groundwater?),
             | child protective services (are you really storing nuclear
             | material in reach of children?!), drug enforcement (are
             | these parties near your "glo fridge" legal and above
             | board?)...
             | 
             | On the bright side, as the joke goes, being on the radar of
             | government agencies is a good way to deter criminals from
             | robbing your house.
        
             | lostlogin wrote:
             | According to the below, The Perseverance could potentially
             | give you a dose of 210 milligram in an accident. That's not
             | as much as I'd have thought, though would make getting the
             | milk from the nuclear fridge a little hazardous.
             | 
             | https://mars.nasa.gov/mars2020/spacecraft/rover/electrical-
             | p...
        
               | cosmonaughty wrote:
               | Galen Windsor and his colleagues worked elbow deep in
               | plutonium and uranium for years. None of them ever got
               | sick. There are some old Galen Windsor videos on YouTube.
               | He traveled around the country eating uranium in front of
               | his students and audience. The EPA of his day had hissy
               | fits. Great stuff!
        
               | JaimeThompson wrote:
               | Eating unprocessed uranium order that isn't giving off
               | very much radiation is a bit different. It just passes
               | out of his body without bioaccumulating.
               | 
               | Source for the claim he worked around plutonium "elbow
               | deep" please.
        
           | souprock wrote:
           | We used to power pacemakers this way. There might still be a
           | person with plutonium inside.
        
       | mytailorisrich wrote:
       | > _All images copyright Nasa /JPL-Caltech_
       | 
       | Question: Aren't those pictures actually in the public domain as
       | they were produced by US government's agencies?
        
       | idlewords wrote:
       | I get how exciting this is for planetary scientists, but the last
       | few robotic missions have really driven home that Mars is kind of
       | an armpit. Here's to sending rovers somewhere with cooler
       | visuals. I will stay up all night to see what the Io Lander can
       | send home before it falls into a volcano.
        
         | wayanon wrote:
         | Not kidding someone could add filters to the images to see
         | different aspects of the view.
        
           | idlewords wrote:
           | Cat filter would make headlines
        
       | Nelkins wrote:
       | I hope we start terraforming Mars in my lifetime.
        
         | birdyrooster wrote:
         | I hope we figure out how to terraform Earth first
        
       | kgrimes2 wrote:
       | All ya'll complaining that you can take better pictures with your
       | iPhones than Percy can on Mars, please read this:
       | https://mars.nasa.gov/mars2020/spacecraft/rover/cameras/
       | 
       | These are ENGINEERING cameras for taking incredibly precise
       | measurements. Not for populating an Instagram page.
        
         | centimeter wrote:
         | > SuperCam fires a laser at mineral targets that are beyond the
         | reach of the rover's robotic arm, and then analyzes the
         | vaporized rock to reveal its elemental composition. Like the
         | ChemCam on rover Curiosity, SuperCam fires laser pulses at
         | pinpoint areas smaller than 1 millimeter from more than 20 feet
         | (about 7 meters) away.
         | 
         | Holy shit, that rocks.
        
           | kgrimes2 wrote:
           | Pun intended?
        
         | cco wrote:
         | If they didn't include at least one Instagram ready camera, the
         | team majorly misstepped on the "secure funding by inspiring a
         | generation" part of NASA's mission.
        
           | kgrimes2 wrote:
           | Go show a kid the EDL video, and then try to say that again
           | with a straight face
        
           | kevin_thibedeau wrote:
           | Such cameras won't survive the trip through interplanetary
           | space and operate on a planet without a magnetic field.
        
       | duxup wrote:
       | Is there a single good official site to get Perseverance media
       | from?
        
         | uomo wrote:
         | https://mars.nasa.gov/mars2020/multimedia/raw-images/ Would be
         | the best place to get images/videos from Perseverance.
        
           | rsj_hn wrote:
           | I want to see that little helicopter fly! I scoured the site
           | and as yet can't find any images of it, when I thought they
           | were going to take mutual selfies -- heli of the rover and
           | vice versa.
        
             | azernik wrote:
             | The helicopter hasn't flown yet - they put it down on the
             | ground, and they're going to run it through a lot of remote
             | checks before flying it. IIRC it's gonna be a month or two
             | before first flight.
        
               | electriclove wrote:
               | I don't believe they have put it on the ground yet.
        
               | rsj_hn wrote:
               | Thank you for this! Do you know of a source on the net
               | for a simple timeline of when X will happen?
        
               | almyk wrote:
               | This is not a timeline, but it states the objectives of
               | the helicopter and contains a check list of them.
               | 
               | https://mars.nasa.gov/technology/helicopter/
        
               | azernik wrote:
               | The ground controllers themselves don't know precisely. I
               | suspect they'll have more precise timelines in the last
               | week before flight, but that's just a wild guess on my
               | part.
        
               | hanniabu wrote:
               | I would think with the wind and sand storms that it'd be
               | dangerous leaving it exposed for a month before you even
               | get to use it. Does the rover park on top of it during
               | storms for minimal protection?
        
               | azernik wrote:
               | Right after landing, Perseverance put Ingenuity down on
               | the ground and drove off to give some separation.
               | 
               | The winds and sand aren't mechanically very strong - the
               | Martian atmosphere isn't dense enough to transmit much
               | force even at high wind speeds. The only real dangers are
               | obscuring the sun (important because Ingenuity runs on
               | solar power) and getting dust in all kinds of places. But
               | the landing site is pretty low latitude, and it's early
               | in northern hemisphere spring right now, so power
               | shouldn't be a problem.
               | 
               | Mars isn't quite as dead as the Moon, but still - you
               | would be surprised how well things are preserved on dead
               | rocks. As long as you can withstand the radiation and the
               | cold, of course.
        
               | gokhan wrote:
               | I don't think Perseverance moved since landing, and
               | Ingenuity should be still inside the rover.
        
               | danaliv wrote:
               | A 60 mph wind on Mars has an aerodynamic drag force
               | equivalent to a 5 mph breeze on Earth.
        
           | WalterSobchak wrote:
           | Also, InSight: https://mars.nasa.gov/insight/multimedia/raw-
           | images/
        
         | [deleted]
        
         | hanniabu wrote:
         | https://mars.nasa.gov/mars2020/multimedia/raw-images/
        
           | Shared404 wrote:
           | This is the link I came to the thread looking for.
           | 
           | Many thanks.
        
       | chovybizzass wrote:
       | they don't look all that stunning to me.
        
         | tiahura wrote:
         | Thanks for having the courage to make this comment. While
         | beauty is in the eye of the beholder, it's not like these are
         | mind bending technicolor panoramas. They look like every other
         | picture of Mars we've seen since the first pictures of Mars
         | decades ago. At some point someone needs to ask why we're
         | spending billions on more pictures of Mars and answering deep
         | questions like "Is Mars soil 36.7 or 36.8% silicon?"
        
           | NL807 wrote:
           | Why? Because missions like these contribute to our
           | understanding of extraterrestrial worlds, like Mars. The data
           | collected will help with future space travel and potential
           | settlement.
        
           | bsder wrote:
           | The "science" mostly isn't in the images.
           | 
           | Images, however, are the easiest thing for the lay public to
           | grasp.
        
             | dimator wrote:
             | Images I would argue serve an invaluable purpose: inspiring
             | the public and the next generation of space explorers.
        
           | perardi wrote:
           | This project will cost $2.8 billion...over the 10-year life
           | of the project.
           | 
           | https://en.wikipedia.org/wiki/Mars_2020
           | 
           | In government terms? That is nothing. We'll burn that much on
           | defective F-35 fighters in a year.
           | 
           | And we are not "just" assessing the mineral content of the
           | soil--not even close.
           | 
           | https://mars.nasa.gov/mars2020/mission/science/
           | 
           |  _(If you're that offended by the cost, I will Venmo you the
           | 0.1 cents per year this is taking out of your tax bill.)_
        
             | medium_burrito wrote:
             | You triggered the fuck out of me. The saving grace of the
             | Joint Strike Jobs program is that maybe 1% of the people
             | learned what to do next time.
        
               | perardi wrote:
               | Yes yes, I know, it's trite to point out that boondoggle
               | of a project.
               | 
               | Except...NASA apparently spent all of $80 million on a
               | helicopter that will work on Mars. One has to wonder what
               | the military-industrial complex could accomplish with a
               | bit of financial discipline and oversight.
        
               | AnimalMuppet wrote:
               | The NASA helicopter had to work _at all_ on Mars. It 's
               | amazing that they succeeded. But it didn't have to
               | survive in an environment with Martian SAM sites, or even
               | rifle fire from the ground.
               | 
               | That is, the military requirements are much more intense
               | than we often realize.
        
               | evilos wrote:
               | Surviving rifle fire has been a solved problem since
               | like, the bronze age. Add more metal. Getting to and
               | landing on another planet (intact and functional) on the
               | other hand, is probably like 3 orders of magnitude higher
               | in difficulty.
        
               | medium_burrito wrote:
               | Inquiring minds would love to know about a practical
               | solution. You can add more material, but that's extra
               | bulk and weight. I think we can agree that a mountain is
               | bullet proof, but that's not really practical.
               | 
               | Also, rifles are really good at shooting through shit.
               | We're talking rifles from 1890s. People don't realize
               | that a bullet from a rifle punches through steel plate
               | (and then buy steel body armour like the plebs they are).
               | Modern ar15/ak rifles are wusses by comparison- we traded
               | big badass bullets for smaller ones that are lighter and
               | easier to carry.
               | 
               | More awesome weapons like the rpg-7 basically create a
               | stream of molten metal that goes right through armored
               | vehicles. Or you use depleted uranium or tungsten, which
               | get more dense as they heat up from friction of punching
               | through things.
               | 
               | In the near future we'll have even more badass things
               | like railguns that will go through meters of
               | steel/ceramic/admantium.
               | 
               | So yeah, that mountain may not save you. Meanwhile, mars
               | will be the same.
        
               | maximente wrote:
               | great: i'm thrilled that the RPG-7, a weapon that is over
               | half a century old, is so awesome. let's cancel all US
               | variants of this tried and true beast and send the money
               | directly to NASA: win-win all around, except by those
               | developing unneeded RPG-7 improvements.
        
               | selimthegrim wrote:
               | Might as well farm that one out to the Pashtuns too -
               | they seemed to be doing OK with the 1890s rifle copying
               | in the 1980s
        
               | evilos wrote:
               | Not really sure how this relates, but ok.
               | 
               | The vast majority of combat causalities are from
               | explosive fragmentation anyways.
        
               | medium_burrito wrote:
               | The whole get 10+ prototypes from various places, stick
               | them in a big ass vacuum chamber, and try to make them
               | fly was interesting. Turns out a torque rotor doesn't
               | work there.
               | 
               | With $80m, the military industrial complex would figure
               | out that pink and yellow don't work well for urban
               | camouflage.
        
         | abledon wrote:
         | yer dopamine circuits are fried brah! Take a tech detox for 2
         | weeks
        
         | AnimalMuppet wrote:
         | What do you want before you'll call it "stunning"? Beaches with
         | women in bikinis? Those are stunning for the amount of detail
         | they show of the surface of another planet.
        
           | m463 wrote:
           | Are you saying women are from mars? I thought they were from
           | venus.
           | 
           | Here are the images:
           | 
           | https://mars.nasa.gov/mars2020/multimedia/raw-images/
        
             | ElCapitanMarkla wrote:
             | Oh wow I didn't realise that was a thing, that's amazing.
             | Thanks
        
           | medium_burrito wrote:
           | Microbes in bikinis, please
        
             | ncmncm wrote:
             | I think this is the first probe _ever_ to have a microscope
             | on board.
             | 
             | Seemed kinda dumb to be looking for evidence of life
             | without one. But there was a time when it was a big uphill
             | battle even to get a camera on board: "no scientific
             | value". That mistake was not repeated. Pictures always have
             | surprises.
        
             | AnimalMuppet wrote:
             | LOL. Not sure why you're being downvoted - microbes with or
             | without bikinis would _definitely_ be stunning.
        
       | known wrote:
       | Mars surface looks pretty much like Earth surface :)
        
         | arethuza wrote:
         | Wait until we get images of cliffs of Echus Chasma, the crater
         | of Pavonis Mons or the view over Valles Marineris....
         | 
         | Edit: I know Perseverance isn't going to those places, but
         | something/someone will eventually....
        
         | novaRom wrote:
         | Like Venus as well. IMO Venus is more interesting destination
         | because it's more active and diverse, with Earth like gravity,
         | but high temp and pressure is the reason we don't land there,
         | Mars is just simpler to explore with current tech.
        
       | suyash wrote:
       | Can someone explain, is this how Mars would look to us with naked
       | eye or this is an artistic/digital interpretation?
        
         | CharlesW wrote:
         | My understanding is that these are how they'd look with the
         | naked eye. There's a color calibration target on the rover.
         | 
         | https://mars.nasa.gov/resources/25619/mastcam-z-looks-at-its...
        
       | etaioinshrdlu wrote:
       | Does anyone know what type of data compression is being used to
       | transmit these images? There's been huge progress since the last
       | rover.
        
         | Denvercoder9 wrote:
         | > There's been huge progress since the last rover.
         | 
         | One thing that changed in the last 8 years is that there are
         | now two new orbiters around Mars (MAVEN and ExoMars TGO), which
         | can retrieve data from the rovers faster, cache it and send it
         | to Earth faster.
        
         | NL807 wrote:
         | I'm speculating here, but I think these images are transmitted
         | in some kind of raw format, or close to it, making them more
         | resilient to data corruption. Compressed images will incur
         | greater data loss when compressed, compared to raw images where
         | you might lose a few image blocks at a time.
        
           | Robotbeat wrote:
           | They compress them but transmit with forward error
           | correction. They do have the ability to retransmit if the
           | images are too damaged.
           | 
           | Totally uncompressed images are not a very efficient way to
           | transmit images if you want to ensure they're scientifically
           | accurate.
        
           | kadoban wrote:
           | Naively, I'd doubt that. There are all kinds of error
           | correcting codes to deal with that and you'd end up with a
           | substantial increase in effective bandwidth (with the
           | compression). There may be error correction built in to the
           | protocol itself already.
        
           | sandworm101 wrote:
           | Compression can also include backup/padding/parity data to
           | correct for errors and transmission losses.
        
         | Robotbeat wrote:
         | They use the same kind of compression as the last mission. JP2,
         | I believe. https://en.wikipedia.org/wiki/JPEG_2000
         | 
         | I'm not sure that data compression has progressed that much
         | since Curiosity in 2012 or Insight in 2018. There have been
         | some formats that have improved compression at the expense of
         | large amounts of memory or processing power, but neither of
         | those are abundant on a rad-hardened processor. Neither is
         | electricity. Neither are the toolchains to process such images
         | very widespread or as well understood.
        
           | hanniabu wrote:
           | Any idea how much storage it has? I would think it'd have to
           | be TBs to store all these images, logs, and other data for
           | years while making sure they have enough memory so that
           | they're not limited and if the rover stays there for longer
           | than intended.
        
             | Hnrobert42 wrote:
             | Why would it need to continue to store things after
             | successful receipt on Earth?
        
               | leephillips wrote:
               | Very off-site backup.
        
             | azernik wrote:
             | Once it's been sent to Earth, they drop it. Curiosity's
             | main computer had a flash drive of 2GB, and each of the big
             | cameras had an 8GB flash drive on board. I doubt
             | Perseverance is much changed from that; the main computer
             | is IIRC a spare part from the Curiosity production.
             | 
             | Rad-hardened computer hardware is expensive and bulky. You
             | don't add storage or processing power that you don't
             | absolutely need.
             | 
             | See https://www.ontrack.com/en-us/blog/how-to-store-data-
             | on-mars and
             | https://mars.nasa.gov/mars2020/spacecraft/rover/brains/
        
           | walrus01 wrote:
           | One of the obvious constraints is that for science reasons
           | they transmit each image in a lossless format, so we're up
           | against the limits of what a lossless image compressor can
           | do.
           | 
           | If there were a future mission's requirement to send back
           | lossy images first, and CPU power was significant, something
           | like AVIF or JPEG-XL would likely be a candidate.
           | 
           | https://netflixtechblog.com/avif-for-next-generation-
           | image-c...
           | 
           | ICER appears to be what they're using now for lossless:
           | https://en.wikipedia.org/wiki/ICER
        
             | mleonhard wrote:
             | According to the graph on p.42, the 20 MHz CPU compresses
             | at a rate of about 20us/pixel. So the 1024x1024 images take
             | about 20 seconds each to compress.
             | 
             | There are 2,000 "normal" sized images on the website [0].
             | If each of these was 1024x1024, they took 11 hours to
             | compress. So Perseverance spends about 7% of its CPU time
             | on image compression.
             | 
             | [0] https://mars.nasa.gov/mars2020/multimedia/raw-images/
        
             | topkeks wrote:
             | AVIF has a lossless mode, which is quite a lot better than
             | PNG for example.
        
             | Robotbeat wrote:
             | Thanks for that. Yes, they do both lossless and lossy
             | compression. I think sometimes they may send the lossy
             | image (especially if for a navigation or engineering
             | camera) and request a lossless image if there's something
             | particularly interesting.
        
           | ptstomp wrote:
           | I can't find references to JPEG 2000 on this report:
           | https://link.springer.com/article/10.1007/s11214-020-00765-9
           | 
           | Are they being re-encoded into regular JPG files when being
           | shown online?
        
             | Robotbeat wrote:
             | Look for "JP2". It is used for other spacecraft that are
             | part of the Mars fleet.
        
       | idiocrat wrote:
       | All the extraterrestrial expansion, dream of Men to conquer
       | Space, star track enterprise! I'm pessimistic that we will ever
       | leave our solar system, and if so in 1000 years, I do not care.
       | 
       | Hopefully people learn how tiny our bubble is and protect our
       | environment more. The Martian environment looks so boring -- as a
       | replacement for polluted Earth. (We will pollute Mars faster than
       | Earth).
       | 
       | I'm living at the ocean, trying to keep my vicinity free of
       | garbage. Today I pulled out pair of trousers and some plastic
       | bands out out water. Sometimes I'm having fights with my elderly
       | village neighbors, who are burning household trash (paper, wood)
       | on the ocean shore. I take their garbage out their hands and
       | carry it to my home, later drive to the garbage processing
       | center.
        
         | moltar wrote:
         | I admire your efforts to clean. But unfortunately it's
         | pointless. There are entire million and billion population
         | countries that treat oceans as waste baskets, simply because
         | they don't know better.
         | 
         | I've talked to fishermen in rural Thailand and they don't have
         | waste collection. So they take their trash every day and just
         | dump it in the middle of the ocean somewhere. They didn't
         | understand why that was a problem when I discussed it with
         | them.
        
           | 0x003 wrote:
           | One person doing something in the face of billions of others
           | is the entire opposite of pointless. Giving up because you're
           | one person and you can't magically transform the entire world
           | is cynical, a cop-out and completely misunderstands the
           | nature of the problem.
           | 
           | The world won't change overnight, it won't immediately flip
           | from the actions of one individual, or two, or even 1
           | thousand or 1 million. But that doesn't mean the action is
           | pointless.
           | 
           | Change requires momentum, momentum requires the actions of an
           | individual diligently living the change they want to see and
           | sharing it with others. That sort of change builds slowly,
           | often imperceptibly. But before you know it things begin
           | _actually_ changing. So no, this binary attitude of  "You
           | can't change everything by your actions so you may as well do
           | nothing" is such an apathetic, cynical cop-out and I hate
           | seeing it spouted everytime you see someone do something
           | positive. As an idea it literally does nothing but harm and
           | it has no value in being said.
        
             | daave wrote:
             | It's not pointless, but I do think it's reasonable to
             | question whether this is the _best_ thing one can do to
             | have an impact.
             | 
             | Could the time spent taking the neighbors trash away be
             | spent doing something even more impactful?
             | 
             | Is the interaction with these neighbors caring and
             | educative, or antagonistic? In the latter case they're
             | unlikely to emulate it or pass on the idea to others.
        
               | 0x003 wrote:
               | It's not about doing the _best_ thing, it 's about doing
               | _something_. You don 't have to perfectly efficient, just
               | take simple actions that reflect the change you want to
               | see. We all have limited time and energy, if you see
               | something positive you can do you shouldn't dismiss the
               | idea of doing it just because you could sell all your
               | belongings and become an eco-warrior and be maximally
               | efficient in pursuing a positive development. Don't do
               | nothing because you could be doing more. Just do what you
               | can.
               | 
               | Do something good and do it consistently.
        
               | solipsism wrote:
               | Why though, if you're not going to make a difference? Why
               | bother?
               | 
               | The reality is that the reason we do these things is to
               | make ourselves feel better. Ah, yes, my daily shot of
               | endorphins from recycling. Ah yes, my bumper sticker
               | makes sure everyone knows I'm one of the good ones -- my
               | social standing is safe.
               | 
               | This philosophy is why middle class first world kids pay
               | thousands of dollars to go on missionary trips to build a
               | single well in a far away village. Yes, you got dirty
               | with the natives and _did something_.
               | 
               | I think it's all hollow. If you aren't making a real
               | impact -- actually moving the needle -- you are doing
               | nothing. It's just a vanity.
               | 
               | I believe in donating money to causes that have high
               | impact. Given my skillset, I'm confident that's by far
               | the best thing I can do. And aside from that, I don't
               | sweat the small stuff. I have a keurig. Yep you heard
               | right. Also donated enough to save a few lives from
               | malaria. Exactly one of those facts about myself made any
               | difference at all to the world.
        
               | 0x003 wrote:
               | > The reality is that the reason we do these things is to
               | make ourselves feel better. Ah, yes, my daily shot of
               | endorphins from recycling. Ah yes, my bumper sticker
               | makes sure everyone knows I'm one of the good ones -- my
               | social standing is safe
               | 
               | Speak for yourself my friend. The idea that people only
               | make changes, even little ones entirely out of self
               | service is extraordinarily cynical and a very negative
               | and sad view of the world.
               | 
               | Sometimes people just do good things, because they want
               | to improve some minor aspect of our world, or make
               | someone elses (or somethings) day a little bit nicer.
               | Sometimes people do this entirely without the desire to
               | praise themselves or be praised by someone else.
               | 
               | It still exists, but by it's nature you don't often see
               | it. And if you don't believe it exists, even when you do
               | catch a glimpse of it you wouldn't notice or care.
               | 
               | > I think it's all hollow. If you aren't making a real
               | impact -- actually moving the needle -- you are doing
               | nothing. It's just a vanity.
               | 
               | Say on my walk to and from work every day I pick up one
               | single piece of litter and quietly put it in the bin. I
               | do this every day, 5 days a week, 50 weeks a year. That's
               | 500 pieces of litter. Every day those little actions
               | aren't moving the needle at all, but at the end of the
               | year I've actually managed to make a tiny little nudge to
               | my environment around me. Say I tell my friend and they
               | decide to do the same thing, now it's 1000 pieces of
               | litter. They tell 2 of their friends, now it's 2000
               | pieces of litter. Then I decide to make it 2 pieces of
               | litter, and I tell my friend and they pass it on. Now
               | it's 4000 pieces. They start telling their friends. And
               | so on and so on. The individual action barely nudges any
               | needle, but just because you don't see it doesn't mean it
               | isn't moving some needle even slightly. You just don't
               | have strong enough vision.
               | 
               | > I believe in donating money to causes that have high
               | impact. Given my skillset, I'm confident that's by far
               | the best thing I can do. And aside from that, I don't
               | sweat the small stuff. I have a keurig. Yep you heard
               | right. Also donated enough to save a few lives from
               | malaria. Exactly one of those facts about myself made any
               | difference at all to the world.
               | 
               | You don't exist in a vacuum, and my whole point of all my
               | comments is that individual action drives collective
               | change. One person making minor adjustments on it's own
               | is nothing, but if many of those singular people decide
               | to make changes it can lead to amazing things. You can
               | choose to make whatever change you please, I'm glad you
               | believe in some action. But let me ask you, what change
               | do you think you're making by stomping on the idea that
               | multiple little changes can lead to positive effects? Why
               | expend the energy if it's pointless anyway?
               | 
               | Things can be better, and people should try and make as
               | many little positive changes as they can to the world. No
               | person is smart enough, or has enough foresight or
               | knowledge to be able to predict what that may lead to in
               | the future, and personally I choose to be optimistic
               | because why waste my life believing that anything better
               | is a futile mission?
        
               | solipsism wrote:
               | _The idea that people only make changes, even little ones
               | entirely out of self service is extraordinarily cynical
               | and a very negative and sad view of the world._
               | 
               | You keep saying that. It's subjective, and it's not an
               | argument. George Bernard Shaw said, _The power of
               | accurate observation is commonly called cynicism by those
               | who have not got it._
               | 
               |  _Say I tell my friend and they decide to do the same
               | thing, now it 's 1000 pieces of litter. They tell 2 of
               | their friends, now it's 2000 pieces of litter. Then I
               | decide to make it 2 pieces of litter, and I tell my
               | friend and they pass it on. Now it's 4000 pieces. They
               | start telling their friend_
               | 
               | Well that's imaginative but it seems highly unlikely.
               | After all, if everyone is so highly primed to change in
               | this way, and all it takes is one person to spark the
               | fire... chances are enormously likely it would have
               | happened already, and it would have happened without you
               | needing to spark it.
               | 
               | This idea that you're at the center of a movement to
               | change the world is just more subconscious ego feeding.
               | If you want to be at the center of a movement that
               | changes the world... it's going to take a lot of hard
               | work.
               | 
               |  _what change do you think you 're making by stomping on
               | the idea that multiple little changes can lead to
               | positive effects_
               | 
               | Humans enjoy conversation, and some of them enjoy trying
               | to figure out truth from fiction. No more, no less.
               | 
               |  _personally I choose to be optimistic because why waste
               | my life_
               | 
               | Whatever floats your boat. We "cynics" are enjoying the
               | ride as much as anyone. We just think we're doing it in a
               | clear-eyed way.
        
               | 0x003 wrote:
               | > George Bernard Shaw said, The power of accurate
               | observation is commonly called cynicism by those who have
               | not got it.
               | 
               | I think you should double check to make sure your
               | "accurate observation" and "clear eyed" thinking is not
               | tainted by your own biases. It's very easy to consider
               | ones own view the accurate one without ironing out the
               | biases learnt or inherent to you.
               | 
               | > Well that's imaginative but it seems highly unlikely.
               | After all, if everyone is so highly primed to change in
               | this way, and all it takes is one person to spark the
               | fire... chances are enormously likely it would have
               | happened already, and it would have happened without you
               | needing to spark it.
               | 
               | They have. Millions of times in fact! Human history is
               | always changing and growing from little things and big
               | things too. The world of today looks drastically
               | different to that of 30 years ago, or 90 years ago or 500
               | years ago!
               | 
               | > This idea that you're at the center of a movement to
               | change the world is just more subconscious ego feeding.
               | If you want to be at the center of a movement that
               | changes the world... it's going to take a lot of hard
               | work.
               | 
               | It's not about being the center of a movement to change
               | the world, and the fact you keep jumping back to that
               | shows that you don't understand what I'm saying. You look
               | at it in that lens because you want to, but it's just
               | about doing minor good things for it's own purpose. A
               | simple autotelic action. It's honestly that simple, but
               | the end result of a lot of people making that simple
               | choice _is_ a changed world. It 's not about feeding ego
               | at all. It's also not about building a movement, at least
               | not directly. It's about convincing those around you of
               | the value of doing something small that improves things
               | even insignificantly because combined they have massive
               | impact.
               | 
               | Enjoy your "clear-eyed view" of the world, I know you've
               | convinced yourself you're 100% correct.
        
           | heavyset_go wrote:
           | One rural fisherman's garbage production doesn't scale,
           | though. A company owned by a handful of people can put out
           | more pollution than that of millions of rural fishermen.
        
           | jcims wrote:
           | My imagination has a pretty big range for 'rural Thailand',
           | do they have a safe way to dispose of it inland? Subsistence
           | folks, to the extent that it might apply here, get a pass
           | from me.
        
             | rsj_hn wrote:
             | The issue is that 90% of the plastic in the ocean is dumped
             | from 10 rivers in Asia and Africa where the waste disposal
             | system consists of driving a truck up to a river and
             | dumping the trash in. Of the remaining 10%, it comes from
             | Latin American nations that do the same thing.
             | 
             | Meanwhile western people see these masses of trash and
             | plastic in the ocean and conclude the rational response is
             | to ban straws in the western nations that do have effective
             | waste disposal systems that don't consist of transporting
             | said waste to the ocean and dumping it.
             | 
             | So the question is whether the outrage about ocean
             | pollution is harnessed towards effectively addressing the
             | problem or whether it is dissipated in the heat of
             | pointless kabuki rituals that we do to absolve ourselves of
             | guilt, even as the trash in the oceans piles up every time
             | someone in the third world throws something away.
        
               | Clewza313 wrote:
               | A lot of those effective waste disposal systems in the
               | West, particularly for recycling, consist of paying Asian
               | and African companies to take away the waste, so it can
               | then be dumped in their countries/oceans or get
               | "recycled" in places like this:
               | https://en.wikipedia.org/wiki/Agbogbloshie
        
               | Invictus0 wrote:
               | From your own source:
               | 
               | > While numerous international press reports have made
               | reference to allegations that the majority of exports to
               | Ghana are dumped, research by the US International Trade
               | Commission found little evidence of unprocessed e-waste
               | being shipped to Africa from the United States,[9] a
               | finding corroborated by the Massachusetts Institute of
               | Technology, Memorial University, Arizona State
               | University, UNEP, and other research.[10] In 2013, the
               | original source of the allegation blaming foreign dumping
               | for the material found in Agbogbloshie recanted, or
               | rather stated it had never made the claim that 80% of US
               | e-waste is exported.[11]
        
               | rsj_hn wrote:
               | No, that is not a waste disposal system, it's how tech
               | companies and other companies that sell gadgets fool
               | their eco customers into thinking they are "recycling"
               | something that cannot in principle be safely recycled. It
               | is yet another example of going through a kabuki ritual
               | rather than effectively dealing with the problem.
        
               | burntoutfire wrote:
               | It's not only recycling. Currently, in my area of Poland
               | there are gangs which bring toxic industrial waste from
               | Western Europe in large quantities and just dump them
               | wherever, while collecting the fee from industrial
               | clients for properly disposing of them. This is a very
               | recent trend, that was, from what I've read, started by
               | China no longer importing European waste. You can only
               | imagine how often "disposing of" such waste in China
               | consisted of dumping it into a forest or pouring into
               | ground or a river.
        
               | Clewza313 wrote:
               | Agreed, but weren't you claiming earlier that poor
               | countries are responsible for 100% of the plastic waste
               | problem?
        
               | rsj_hn wrote:
               | I think that's a good approximation. The volume of
               | computer parts or used phones isn't significant compared
               | to the total volume of waste produced domestically in
               | these nations. But it's a separate tragedy that companies
               | like Apple can pay partners to "recycle" stuff that ends
               | up in a landfill in Nigeria somewhere, or manually
               | stripped of copper and other parts by people working in
               | unsafe conditions.
        
               | BelenusMordred wrote:
               | Plastic recycling done in Asia is the result of
               | incredibly cheap return shipping as most containers come
               | back empty.
               | 
               | People who get outraged about it don't understand that
               | due to cheaper wages and energy costs, plus the need for
               | raw feedstock in the manufacturing countries it's
               | actually a really decent system. It's a closed loop where
               | plastic goods are produced in Asia and recyclable plastic
               | returns on the same ship, it gets processed and keeps raw
               | material prices low for continued use in manufacturing
               | for export again. It doesn't just get shipped there and
               | thrown in a river.
               | 
               | The real problem, especially in South East Asia is very
               | much cultural, many assumed that societies would become
               | more environmentally friendly as they got richer but that
               | is not the case, they are polluting more than ever. It's
               | incredibly common to see people throw rubbish on the
               | ground despite being right next to a bin. Nearly every
               | waterway is horrendously polluted with plastic consumer
               | products.
               | 
               | It's an externality that the rest of the world must bear.
               | The other poster here is on the money, nearly all of it
               | comes from a few catchments.
               | 
               | Half the plastic in the ocean comes from 5 countries, all
               | are in Asia.
               | 
               | https://www.weforum.org/agenda/2018/09/asia-s-plastic-
               | proble...
        
               | Clewza313 wrote:
               | That's the theory. However, in practice plastic recycling
               | waste is contaminated & worthless, so much so that a
               | number of Asian countries including China and Malaysia
               | have banned imports.
        
             | vlovich123 wrote:
             | What's the waste stream looking like? Like can we trace how
             | this trash originates and why it's not ending up where it
             | should? If poor areas with weak government services _are_
             | the problem, then that's a problem, no?
        
           | neolog wrote:
           | What could they do with the waste instead, if they don't have
           | collection?
        
             | jpindar wrote:
             | In parts of the US that don't have garbage collection,
             | people are expected to either take it to a dump or bury it
             | on their own land.
        
             | hanniabu wrote:
             | Honestly burning it just might be better. Without doing any
             | calculations my intuitions tell me it would be minuscule on
             | the global scale and the benefit of that garbage not going
             | into the ocean would outweigh the added air pollution.
        
           | blondie9x wrote:
           | If one million people make a little effort the impact will be
           | huge. Dont't be pessimistic. Lead by example. The simplified,
           | minimalist, sustainable living style is contagious because it
           | is as we are meant to actually live. In balance with the
           | energy of the planet we depend upon and are part of.
        
         | wait_a_minute wrote:
         | The only solution is the spread of information and education.
         | That's the only thing that will help. We must reach all people
         | and present them with the evidence on environmental
         | degradation. The planet is ours to protect and cherish, and I'm
         | confident this is an achievable goal if we act fast. By
         | advocating for access to internet and education at global
         | scale! Starting with our homes.
        
           | mLuby wrote:
           | "One person's trash is another's treasure."
           | 
           | The other solution is make it more _profitable_ to collect
           | and sell your garbage than to dispose of it. Which means it
           | has to be worth it for a business to collect your trash from
           | you. Better recycling and distribution technologies can
           | enable this.
           | 
           | I dream of the day when businesses fight for the privilege of
           | hauling away your trash. Maybe delivery drones could bring
           | back garbage to make their return trips less, uh, _wasteful._
        
             | runarberg wrote:
             | nah. We've been waiting for businesses to step up their
             | game for over 30 years now. I don't see it happening in the
             | next thirty years coming. A more realistic scenario is for
             | governments to build the infrastructure required to recycle
             | and reuse our trash and, better yet, regulate how trash is
             | produced and punish it's existence.
        
               | wait_a_minute wrote:
               | This. Fuck that. Anyone under 65 can agree with me. It's
               | us and our kids and their kids for the next 50-100 years
               | that will pay. Time for us to take the reigns. These fat
               | cows had their chance. We'll build a garden.
        
               | mrmonkeyman wrote:
               | They don't need to "step up their game", they are plenty
               | efficient at minmaxing the economic game. If anything the
               | government and thus the people need to step up their game
               | to change the incentives.
        
             | wait_a_minute wrote:
             | Profit has been a deprecated concept. Technology we have
             | today can automate Maslow's hierarchy of needs for all at
             | global scale.
        
               | wiz21c wrote:
               | Maslow. You mean the guy who took babies ape away from
               | their mother ?
        
         | sytelus wrote:
         | Most people are unable to realize distances in space. Humans
         | are simply not designed to travel in space. For a space ship
         | that can be self-sustaining in every way and capable of multi-
         | year travel, it has to be almost like a city. Even when you get
         | to planets, they are even less hospitable than Mars. I think
         | future life forms which will colonize other planets will be
         | machines, not humans.
        
           | yellowapple wrote:
           | > I think future life forms which will colonize other planets
           | will be machines, not humans.
           | 
           | Tardigrades seem like likely candidates, too.
        
           | nostromo wrote:
           | Most people also don't realize how slow the speed of light is
           | in relation to the size of the universe and the distance
           | between stars. It's quite easy for a person to look at two
           | galaxies in a telescope that will never be able to even
           | observe each other's existence, let alone visit one another.
           | 
           | People often argue that we'll find a way to travel faster
           | than light -- which is curious given how rarely people argue
           | that we'll find a way to travel backwards in time.
        
         | Trasmatta wrote:
         | > We will pollute Mars faster than Earth
         | 
         | I don't see how this is possible. At most, Mars might have
         | small, organized colonies someday. Earth has billions of
         | people.
        
       | gtm1260 wrote:
       | Stupid question maybe but like is there a reason the picture
       | quality seems worse than a decent dslr photo? I'm so curious what
       | that photo would look like, taken with an everyday camera,
       | without the bizarre 'scientific' look of these shots.
        
         | antmldr wrote:
         | Scott Manley recently did a pretty good ELI5 on the topic:
         | https://www.youtube.com/watch?v=Wah1DbFVFiY
        
           | dmix wrote:
           | It takes 15min but this plus the comment section on CMOS
           | (can't link directly) is excellent. The other comment about
           | being made a decade ago is also relevant and accurate. They
           | will certainly be better next time with evolutions in camera
           | tech thanks to smartphones.
           | 
           | TLDR worth a listen
        
         | pkaye wrote:
         | In some interviews with the mast cam engineers, they say they
         | can capture higher resolution images later on. Maybe they were
         | reducing the image size to get then transmitted quicker.
        
         | cosmonaughty wrote:
         | The video has to be grainy. Otherwise it's much easier to see
         | that it's fake.
        
         | dmix wrote:
         | My question is why was the "sound of Mars" release only 18
         | seconds long?
         | 
         | Why not record hours of what it sounds like to be on another
         | planet? Even the sound recordings from decades ago on (I think
         | Titan) was only a short creepy clip.
         | 
         | I understand it's mostly going to be wind and interspliced with
         | the robots sounds but I still don't get how we don't have hours
         | of Mars already.
        
           | athul7744 wrote:
           | Perseverance is the first rover with microphones on Mars.
           | This is why we don't have audios from prior missions.
        
             | m4rtink wrote:
             | IIRC the Mars Insight mission was able to reconstruct the
             | sounds of wind in Mars from signals picked up by their
             | super sensitive seismometter.
        
             | nkoren wrote:
             | _Working_ microphones. They 've sent microphones
             | previously, which have either failed or been on missions
             | that crashed.
        
           | cosmonaughty wrote:
           | With atmospheric pressure less than 1% of Earth's, there
           | would be virtually no sound. Sound travels as vibrations
           | between air molecules. If you're hearing sound on Mars then
           | you're not on Mars.
           | 
           | With 100x thinner air, the air molecules would not even be
           | close enough to forward such vibrations. You wouldn't be able
           | to hear a gunshot a few feet away.
           | 
           | The fact that NASA would provide any sound at all just
           | demonstrates this is all a staged fakery, being done here on
           | earth with a bit of augmented virtual reality to spice up the
           | film. Since sound doesn't travel in 1% atmosphere the way it
           | does in real earth atmosphere, you should hear virtually
           | nothing.
           | 
           | This whole affair is a Hollywood sci-fi production being sold
           | to you as science. You want so deeply for it to be real that
           | cognitive dissonance and Dunning Kreuger will likely cause
           | you to have a visceral reaction to my remarks. That's OK.
        
           | histriosum wrote:
           | My guess would be bandwidth. Every bit of bandwidth is
           | precious, so they probably dont have the spare budget to send
           | long audio files without obvious scientific value...
        
             | gambiting wrote:
             | Yes, but you could record few minutes of sound in the same
             | amount of data taken by one high res photo. I think the
             | good question is why 18 seconds specifically.
        
               | simonh wrote:
               | It's just 18 seconds so far. I doubt they sent the
               | microphone just so they could use it once, but then I
               | doubt sending hours of audio was at the top of the
               | priority list for the first few days of the mission.
        
             | TeMPOraL wrote:
             | Maybe after they complete their primary and secondary
             | mission objectives, they'll find spare time and compute to
             | stream a couple hours of Martian ambience. Does NASA have a
             | suggestion box for after hours / extended program
             | experiments?
        
               | zaik wrote:
               | I doubt a NASA suggestion box open to the internet will
               | be very fruitful.
        
               | dmurray wrote:
               | I for one look forward to Rover McRoverface in the 2022
               | launch window.
        
               | bregma wrote:
               | Marvin McMarsface is to take a close-up look at the Face
               | On Mars in 2023 and then implant an Illudium Q-36
               | Explosive Space Modulator to eliminate Mars because it
               | obstructs our view of Venus.
        
               | HenryBemis wrote:
               | > I doubt a NASA suggestion box open to the internet will
               | be very fruitful.
               | 
               | The two resectful and fun comments between 'this' comment
               | and your comment.
               | 
               | I can imagine a Tumblr/Reddit re-post would be more fun,
               | but-yes-not for the NASA suggestion box. They would have
               | 1 diamond idea every 100k unusable ones.
               | 
               | I can imagine every gaming company would LOVE to have the
               | original Mars sound in their games (e.g. "No Man's Sky").
        
               | C4stor wrote:
               | In a world where the sounds of sports on TV is not even
               | the true sound of what's happening in the stadium because
               | it's boring, I highly doubt they would pay a single penny
               | for what would probably be a highly disappointing wind-
               | like monotonous sound.
        
           | carapace wrote:
           | One of the most beautiful and haunting things I've ever heard
           | was a tape cassette that had EM signals recorded by Voyager
           | transposed into human-audible sound domain somehow. It was
           | like whale song of space.
        
             | dmix wrote:
             | I found it here (there's a series on other planets/moons as
             | well in the recommendations):
             | 
             | https://www.youtube.com/watch?v=LIAZWb9_si4
             | 
             | And Cassini flying into Saturn
             | https://www.youtube.com/watch?v=hWHLCHv4PiI
             | 
             | I wonder what it sounds like to leave the atomosphere now
             | too, I guess this is as close as we can get in the near
             | future. Even with probes going 15km/s.
        
         | Symbiote wrote:
         | Is it simply dusty/hazy?
         | 
         | Some of the fuzzy photos remind me of the Sahara Desert when
         | there was a little wind.
        
           | OrbitRock wrote:
           | Dusty. Gives the sky a dull reddish color. Also makes Martian
           | sunsets blue.
        
         | phonethrowaway wrote:
         | speculation, but it's probably compressed before transmission
         | to earth... for obvious reasons.
        
           | [deleted]
        
           | alpaca128 wrote:
           | It would surprise me if they used lossy compression. However
           | I once read about a space probe using a custom image
           | compression and transmission format which does not require
           | 100% data integrity for proper decoding. So if the
           | transmission is cut off after 60% NASA will still be able to
           | view whatever they received. I assume such methods are still
           | applied.
        
         | Balgair wrote:
         | Generally, these cameras are many years out of date. They don't
         | load up the rovers with the latest gear from today, but with
         | the latest gear from when the design review process was closed.
         | I don't know when that was for Perseverance, but it would not
         | surprise me if that was a decade ago. The cameras are also not
         | specifically designed for image capture, but for scientific
         | study. In that they take images at a wider range of wavelengths
         | than what humans can see. It's a subtle difference, but an
         | important one. Additionally, the cameras' chips are not what we
         | have commercially. They are designed to withstand the vacuum,
         | the solar radiation on the long transit, and for use on the
         | Martian surface for many years. You can't swap them out, ever.
         | As such, they are much more 'rugged', which may effect image
         | quality as well.
        
           | reilly3000 wrote:
           | Yep, that's the same reason why it runs on a PowerPC750 chip.
           | They cost $200k+ for under 200Mhz on a 150-250 nm process,
           | but can withstand up to 1,000,000 rads of radiation and
           | function within extreme temperature ranges for decades. They
           | have been proven to work in the harshest environments on
           | prior missions, and the risk of an unproven processor is
           | giant; a CPU failure could jeopardize the mission just as
           | much as a crash landing. Design constrains are so very
           | different when you shoot something 140M miles away!
        
             | wiz21c wrote:
             | Could you explain why such a processor is 1000x more
             | expensive than a non-rugged one ? I mean, considering the
             | future of earth, I'd certainly welcome a processor that
             | could withstand a lifespan of decades (including the harsh
             | "I'm going to unsolder it to put it in another device"
             | environment).
        
               | pja wrote:
               | IIRC it's a custom process using wide-bandgap silicon
               | (part of the whole rad-hardening thing) that no-one else
               | needs or wants, so you have to pay the full costs of a
               | fab run for a relatively small number of chips. Hence the
               | cost per chip is huge.
        
               | ben_w wrote:
               | From this list, I assume the isotopic purity is the
               | biggest contribution to the price, though I expect
               | relative lack of mass production doesn't help:
               | https://en.m.wikipedia.org/wiki/Radiation_hardening
        
               | WarOnPrivacy wrote:
               | Specs: https://en.wikipedia.org/wiki/RAD750
        
               | TeMPOraL wrote:
               | Part of it is low demand, so you don't benefit from
               | economies of scale. Also the customers buying this type
               | of equipment are able to bear such costs. They aren't
               | gonna haggle over $100k on a critical component to a $3B
               | mission.
        
               | dylan604 wrote:
               | a $100k here, a $100k there, suddenly, we're talking real
               | money.
        
               | reilly3000 wrote:
               | Oh we're talking real money. JPL will destroy 78
               | production grade parachutes to find all the ways they can
               | break. There is tremendous energy poured into eliminating
               | risk, because launch is so expensive. As it becomes
               | cheaper, perhaps these measures won't be as necessary.
        
               | derekp7 wrote:
               | With Spacex being able to launch a car out beyond the
               | orbit of Mars, is their current capability being
               | considered for future JPL missions? Or is everything
               | waiting on Starship?
        
               | moftz wrote:
               | The low demand definitely leads to higher prices but the
               | other aspect is all of the additional testing involved
               | for every chip. There's standard testing at every level
               | of the manufacturing process and there will be further
               | environmental testing at the package level. They will
               | even run radiation tests on the wafer to characterize any
               | quirks.
        
               | m4rtink wrote:
               | Hopefully as more space & deep space stuff gets going
               | there will be more demand and the unit cost will go down
               | thanks to economies of scale. Or alternatively ways of
               | computing are tried and found viable (massive shielding,
               | standardized massive redundancy, etc.).
        
               | wiml wrote:
               | For radiation-hardened semiconductors sometimes you use
               | specialized processes like silicon-on-insulator. Even if
               | you're using a more conventional process, you're probably
               | using specialized upset-resistant gate designs and
               | layout. And even your gate-level or HDL-level design
               | might have changes to make it possible to detect and
               | recover from some kinds of bitflips. It really affects
               | the whole technology stack.
        
             | velvetz wrote:
             | Maybe a stupid question, but couldn't they put there
             | something "cutting-edge" next to the existing system? Then
             | if that fails then whatever, the rest of the system is
             | still functional as expected, but at least they know that
             | in the future what they would need to change to be able to
             | use the new technologies in that environment. Although I
             | can imagine that even the smallest weight increase could
             | cause issues, so probably that's the reason.
        
               | pkaye wrote:
               | I know the camera image compression happens on a x86
               | processor. Not sure if it is rad hardened. It would be
               | okay if the processor is not doing critical work and can
               | be power cycled due to a rare SEU failure. Also the same
               | with the helicopter uses a mobile phone processor.
               | 
               | Also some of the components are not rated for long term
               | use. The microphones they installed will probably fail
               | due to extreme temperature cycling. The helicopter is
               | expected to last only 4 uses and anything beyond that is
               | a bonus.
        
               | wongarsu wrote:
               | Ingenuity (the Mars helicopter) has a much more modern
               | processor that isn't particularly radiation hardened, and
               | instead just restarts within milliseconds on any fault
               | (fast enough to recover if it happens in flight). If
               | Ingenuity does well I wouldn't be surprised to see a
               | similar design in a future rover.
        
               | grishka wrote:
               | They did this exact thing with the helicopter -- it's
               | using a Snapdragon SoC that runs Linux.
        
               | m4rtink wrote:
               | Scott Manley mentioned in one of his recent videos about
               | Perserverance that they have an FPGA on board the rad
               | hardened PPC main cpu can offload tasks to, such computer
               | vision based navigation during landing.
               | 
               | Not sure what the long term plan is for that hardware - I
               | guess they can just do stuff more slowly on the main CPU
               | if it gets fried by radiation. Or maybe being an FPGA the
               | can just isolate the radiation affected regions over time
               | and use the rest ?
        
               | reilly3000 wrote:
               | You got me curious and I found a product listing with a
               | rather amazing explanation of what they're doing for
               | radiation-proofing.
               | 
               | Radiation Performance
               | 
               | > RTG4 FPGAs are immune to radiation-induced changes in
               | configuration, due to the robustness of the flash cells
               | used to connect and configure logic resources and routing
               | tracks. No background scrubbing or reconfiguration of the
               | FPGA is needed in order to mitigate changes in
               | configuration due to radiation effects. Data errors, due
               | to radiation, are mitigated by hardwired SEU resistant
               | flip-flops in the logic cells and in the mathblocks.
               | Single Error Correct Double Error Detect (SECDED)
               | protection is optional for the embedded SRAM (LSRAM and
               | uSRAM) and the DDR memory controllers. This means that if
               | a one-bit error is detected, it will be corrected. Errors
               | of more than one bit are detected only and not corrected.
               | SECDED error signals are brought to the FPGA fabric to
               | allow the user to monitor the status of these protected
               | internal memories.
               | 
               | https://www.microsemi.com/product-directory/rad-tolerant-
               | fpg...
        
               | m4rtink wrote:
               | Wow, a rad hard FPGA! Now that's something I didn't
               | expect - thanks for digging this up! :)
        
               | josho wrote:
               | But now you've added weight and need to remove something
               | else.
               | 
               | As a tangent, I remember a talk from Grady Booch where he
               | put software cost in terms of mass that needed to be
               | added to your rocket. So every new feature cost weight by
               | requiring more chips and more fuel.
        
             | Cthulhu_ wrote:
             | Especially since hardware is generally designed for speed
             | and performance instead of reliability. Didn't NASA use a
             | lot of 486es for a long time for this same reason?
             | 
             | But yeah. It's not a problem if a CPU gets buggy or dies in
             | a datacenter with 10K similar ones, because of redundancy
             | and a completely different approach to software workloads
             | nowadays. I mean a lot of production systems barely even
             | care what CPU they run on.
             | 
             | And ~200 Mhz is still powerful enough for a LOT of
             | applications.
        
               | darkr wrote:
               | > Didn't NASA use a lot of 486es for a long time for this
               | same reason?
               | 
               | They were also using Amigas until ~2006 for various
               | duties, including launch control.
        
       | soheil wrote:
       | Nasa's image gallery UI is such a pain to use, I wish someone
       | would upload these into a more user friendly photo viewer tool.
        
         | hanniabu wrote:
         | What's difficult about it?
        
           | asdff wrote:
           | Multiple clicks to get to the full resolution image. 50
           | thumbnails able to be viewed at a time, many uninteresting to
           | lay people (solid gray screen, dozens of repeated images of
           | of a portion of the rover itself, etc), for the monumental
           | task of sifting through the 6407 images the rover has
           | transmitted so far in mere days. Wholly unusable in a few
           | months I imagine.
        
             | hanniabu wrote:
             | Maybe over the weekend if I can carve out a few hours I'll
             | put together an open source site and share here.
        
             | kgrimes2 wrote:
             | The site isn't great, no. But the reason there's so many
             | repeated images is because NASA doesn't want to be accused
             | of hiding anything.
             | 
             | If they're taking photos for calibration, we get those,
             | just like if they're taking stunning panoramas.
        
               | phist_mcgee wrote:
               | And to a science agency, I don't think their top priority
               | is selecting the best 4k wallpaper for easy download.
               | 
               | I honestly don't mind government sites, they are usually
               | thoroughly boring and very conservative with their
               | design, which means that even old people like my dad can
               | click around and use it. I think that's a good thing.
        
               | kgrimes2 wrote:
               | That being said, there are NASA sites that are more
               | curated, like https://photojournal.jpl.nasa.gov/beta
        
       | raphaelj wrote:
       | The high resolution, 360 panoramic view, of the landing site is
       | also stunning:
       | 
       | https://mars.nasa.gov/news/8873/nasas-perseverance-rover-giv...
        
       | cosmonaughty wrote:
       | The picture labeled "wind carved rock" is interesting. If the
       | atmospheric pressure is 610 pascals or 0.088 psi (less than 1%)
       | earth pressure, how could any wind be powerful enough to carve a
       | rock? Does the wind blow 600-1200 mph on Mars?
       | 
       | Don't answer as the question is rhetorical.
       | 
       | Air pressure that thin would require winds several hundred MPH
       | just to kick up fine dust particles, well before we get to
       | erosion of rock.
       | 
       | With such low air pressure a human would barely feel a 300 MPH
       | wind gust. In that low air pressure a parachute would be useless
       | unless it is 2000 feet in diameter.
       | 
       | A rocket would need 100x the thrust to get the same acceleration
       | or deceleration, as per Newton's law, 100x less resistance means
       | an object in motion plummeting toward the surface would tend to
       | remain plummeting. Remember why they tell you meteors meet
       | resistance and burn up entering Earth's atmosphere? The reverse
       | would be true of a object plummeting through atmosphere of only
       | 610 pascals. 100x more thrust would be necessary to slow the
       | descent to compensate for the lack of atmosphere and the density
       | differential.
       | 
       | Did NASA think of any of the actual physics before they served
       | you this fake Mars landing cartoon? You're hackers. You know how
       | to do math. This is 8th grade physics to see the scam being
       | served up here as scientific exploration.
       | 
       | I suppose if grifters had a 70 million dollar per week budget
       | they might be tempted to produce what was paid for, even if they
       | had to fake it.
       | 
       | Everything shown to you in these Mars landing videos is
       | consistent with parachuting into Earth's atmosphere, not an
       | atmosphere 100x thinner. That parachute would drop almost as fast
       | as a rocket. Remember the falling feather and cannonball in a
       | vacuum analogy?
       | 
       | You're being played. NASA is just a division of Hollywood. Yes,
       | the world is that messed up. And yes the military industrial
       | complex is that shady.
       | 
       | Enjoy your cartoons!
        
         | king_magic wrote:
         | Mars once had a much thicker atmosphere.
        
         | enlyth wrote:
         | 10/10 satire
        
           | wiz21c wrote:
           | yeah, but as someone not educated in those matters, could
           | someone compare the "fake" computations from the comment to
           | real ones ? So we could see how wrong they are...
        
             | danparsonson wrote:
             | I don't have figures for you, but some food for thought -
             | a) 'wind-carved' rocks are not really carved by the wind
             | itself but by particles carried on the wind, and Mars is
             | regularly subject to large dust storms (see
             | https://www.nasa.gov/feature/goddard/the-fact-and-fiction-
             | of... - sorry it's a NASA link, hopefully everyone can see
             | through the grifting, or whatever), b) the vast timescales
             | involved - who knows how many hundreds of thousands of
             | years that rock has been sitting there, slowly weathering
             | away?
        
             | cosmonaughty wrote:
             | Perfect example of Dunning Kreuger! To answer your question
             | you could get a physics textbook. The numbers I provided
             | you are the official numbers. 610 pascals, or 0.088% earth
             | pressure. A stuffed bear with a normal parachute would hit
             | the ground at terminal velocity with only 600 pascals of
             | air buoyancy.
        
       | [deleted]
        
       | BooneJS wrote:
       | I love seeing cables neatly routed and even evidence of cable
       | lacing in 2021. Dying art.
        
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