[HN Gopher] BepiColombo's First Views of Mercury
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BepiColombo's First Views of Mercury
Author : adolph
Score : 182 points
Date : 2021-10-04 04:57 UTC (18 hours ago)
(HTM) web link (www.esa.int)
(TXT) w3m dump (www.esa.int)
| cletus wrote:
| I see a bunch of confusion about Mercury in this thread so let me
| correct the record.
|
| First, as to why colonize Mercury, there are some really good
| reasons:
|
| 1. Cheap, abundant energy (ie solar);
|
| 2. Access to tons of raw materials, particularly metals;
|
| 3. Relatively low gravity means getting into orbit is relatively
| low cost.
|
| A few people have stated we'd hide in a crater as a negative.
| We'd live underground probably in submerged habitats that spin to
| produce Earth-like gravity, just as we would have to on Mars and
| the Moon.
|
| For Mars in particular, people have this romantic notion of
| living on the surface. We wouldn't. There's essentially no
| atmosphere. Worse than no atmosphere actually there's just enough
| to cover all your gear in dust and do little else for you. You
| still have to worry about radiation. Terraforming is a
| monstrously massive project that would take millenia.
|
| The biggest negative to Mercury is how hard it is to reach from
| Earth. Fun fact: the delta-V required to reach Mercury from Earth
| is more than that to escape the Solar System (eg like New
| Horizons). There's a reason this probe is taking 7 years to get
| there and doing multiple gravity brakes along the way (watch the
| ESA animation [1]).
|
| If you're going to bootstrap a Dyson Swarm, Mercury is almost the
| perfect place to do it from.
|
| [1]:
| https://www.esa.int/ESA_Multimedia/Videos/2017/07/Animation_...
| Loughla wrote:
| Two things from that video:
|
| 1. The amount of planning that is required for this is just
| astounding to me. That we can pretty trivially plan to use
| something like planetary motion as a motor is fascinating.
|
| 2. I'm really bad at Kerbal Space Program.
| harscoat wrote:
| To see how bare the planet is, with so many cosmic impacts...
| makes us wonder how fragile a planet with life is
| lmilcin wrote:
| I am no expert, but I think it is very likely most of these
| craters are from very early life of the planet, before there
| was life on Earth. Orbit of Mercury is very well cleaned of any
| other bodies and must have been like this for billions of
| years.
|
| Because there is no erosion mechanism on Mercury (except for
| crumbling due to temperature changes) these craters were
| preserved perfectly.
| adolph wrote:
| _The closest approach took place at 23:34 UTC on 1 October at an
| altitude of 199 km from the planet's surface._
| noizejoy wrote:
| Albeit the pictures are from at least 1000 km away, since
| closest approach was from the dark side.
| jcims wrote:
| I'm always amazed at the precision of space probe operations.
|
| It's a bummer we don't have better space propulsion systems,
| five years meandering about the inner solar system to get the
| right speed and angle to enter an orbit around mercury.
| KineticLensman wrote:
| It's a bummer we don't have better space propulsion systems
|
| Hey! I used to work for the company that made BepiColombo's
| engines [0]
|
| [0] https://www.qinetiq.com/en/news/pioneering-qinetiq-solar-
| ele...
| jcims wrote:
| Ah now i get the username! :D
|
| Very cool!
| KineticLensman wrote:
| Thank you. It actually started for photography reasons
| when I knew a (friendly) rival photographer who worked
| for one of our customer organizations.
|
| [Edit] That and my liking for the Space Opera novels
| written by E.E. 'Doc' Smith.
| jcims wrote:
| Ah! Nice! Works for photography and for a person that
| builds ion drives. I'll leave you alone now haha.
| Azrael3000 wrote:
| Scott Manley did a great video on the probe and its approach:
| https://www.youtube.com/watch?v=1Sj9cjwFhQY
| jrootabega wrote:
| This is an amazing achievement.
|
| Also, there appears to be a typo in one of the images near the
| bottom. "Lemontov" instead of "Lermontov".
| [deleted]
| entrep wrote:
| Here's a great overview of BepiColombo's journey:
| https://www.esa.int/Science_Exploration/Space_Science/BepiCo...
| TedDoesntTalk wrote:
| > BepiColombo's main science mission will begin in early 2026. It
| is making use of nine planetary flybys in total: one at Earth,
| two at Venus, and six at Mercury, together with the spacecraft's
| solar electric propulsion system, to help steer into Mercury
| orbit. Its next Mercury flyby will take place 23 June 2022.
|
| What a strange mission. Why can't it stay in orbit around Mercury
| now?
| brylie wrote:
| By way of example, here is a video explaining what was needed
| to get the Messenger spacecraft into orbit around Mercury:
|
| https://youtu.be/gBwspxfW10w
| danieldk wrote:
| The Wikipedia page has a nice description of the issues of
| entering Mercury's orbit:
|
| https://en.wikipedia.org/wiki/Mercury_(planet)#Research_with...
| gorgoiler wrote:
| We live in a village at the top of a very steep, mile deep, ice
| covered valley. Mercury is a village at the bottom of the
| valley.
|
| Your house is high up the valley but you actually live thirty
| feet deep in a pit. To get to Mercury you have to build a car,
| lift it out the pit, then slide down the steep valley. The car
| has to be lightweight so that you can lift it out the pit: the
| engine and brakes are weak and do next to nothing.
|
| So you build a feeble car -- more of a four wheeled bicycle
| really, hoist it out the pit, and slide down the valley in it.
| By the time you whizz past Mercury you're doing 100mph so you
| can't stop. You go straight past and start sliding up the other
| side, but you do also put the brakes on for a bit. You'll
| eventually slide back down to Mercury again at 90mph and put
| the brakes on again, and slow down a little more.
|
| Do this ~10x and you'll eventually stop.
|
| Going in the other direction is easier. Earth is surrounded in
| a 100km soft squishy cushion of gas which means to all intents
| and purposes you can just fly straight at it.
| brylie wrote:
| Here is an example of a rocket design/mission in Kerbal Space
| Program that can insert into orbit on the first pass:
|
| https://youtu.be/lYwrbhzj694
| ericbarrett wrote:
| Worth noting the Kerbol* solar system is significantly
| smaller and lighter than the real one, and has fewer
| eccentricities in orbit, axis of rotation for the various
| bodies, and so on. E.g. it takes about 3,300 m/s of v to
| reach orbit around Kerbal, and LKO velocity is ~2200; for
| Earth, about 9,400, with LEO velocity of ~7300.
|
| If you play KSP and would like a challenge much closer to
| real rocketry, check out the Realism Overhaul mod--and don't
| forget Principia. For an actual campaign based on the Apollo
| program, starting in 1951, check out RP-1 (Realistic
| Progression).
|
| * Kerbol is the name of the star
| arethuza wrote:
| It's going too fast and doesn't carry enough fuel to slow down
| directly into orbit.
| pietroppeter wrote:
| > BepiColombo is named after Giuseppe "Bepi" Colombo (1920-1984),
| a scientist, mathematician and engineer at the University of
| Padua, Italy, who first proposed the interplanetary gravity
| assist manoeuvre used by the 1974 Mariner 10 mission, a technique
| now used frequently by planetary probes.
|
| https://en.m.wikipedia.org/wiki/BepiColombo
| davidw wrote:
| I saw that name and I thought "that's a name from the Veneto".
|
| The history of that university is pretty amazing. I can't
| recommend the tour enough, if people go through Padova. It's a
| nice change from all the churches, castles and villas that you
| see elsewhere in Europe.
|
| https://en.wikipedia.org/wiki/University_of_Padua
| ddevault wrote:
| https://en.wikipedia.org/wiki/BepiColombo
| [deleted]
| _boffin_ wrote:
| > comets crashing onto the surface at speeds of tens of
| kilometers per hour.
|
| comets came crashing down slower than one goes in a school zone?
| ladberg wrote:
| For anyone else reading, it's since been updated to "tens of
| kilometers per second."
| [deleted]
| bartvk wrote:
| This is a great mission for mankind as well. A previous HN
| discussion talked about the possibility of a Mercury colony
| because it has water ice.
|
| https://news.ycombinator.com/item?id=27741738
| https://www.universetoday.com/128531/terraform-mercury/
| lmilcin wrote:
| Except colonizing Mercury is of relatively little value because
| of how little surface of it is usable, impossibility of
| terraforming the planet, how difficult it is to get there or
| back and that it does not help to reach any other interesting
| place in our system or outside of it.
| BeefWellington wrote:
| A colony doesn't strictly have to mean "persist humanity
| indefinitely into the future" -- it can also mean going
| there, setting up camp and extracting mineral resources, for
| example.
| lmilcin wrote:
| Why extract mineral resources from a planet that is so deep
| within Sun gravitational field that you have to expend more
| energy to get stuff from there than you would to get stuff
| from Earth surface?
|
| Why do that if you have billions of flying bodies in much
| more convenient places flying around the Sun waiting to be
| docked to to extract resources?
| zardo wrote:
| It would have to be resources for something you either
| leave on Mercury, or leave in solar orbit near Mercury's.
| Denvercoder9 wrote:
| _> Why extract mineral resources from a planet that is so
| deep within Sun gravitational field that you have to
| expend more energy to get stuff from there than you would
| to get stuff from Earth surface?_
|
| Mercury itself is light enough to cancel that out.
| lmilcin wrote:
| > Mercury itself is light enough to cancel that out.
|
| No, it does not cancel it out.
|
| You need about 12km/s delta V to get to Mercury from
| Earth and then the same to get back. Remember, if you
| need to lift anything from Mercury, you need to actually
| transport fuel TO Mercury, before you can use it to lift
| anything out of Mercury.
|
| And you don't just need twice more fuel for twice more
| delta-V. The fuel requirements grow _exponentially_.
|
| Now imagine, how poor idea it is to transport mountains
| of fuel to Mercury just to get a tiny bit of what
| exactly? Raw materials? What kind of raw materials are
| present on Mercury that would warrant it?
| Denvercoder9 wrote:
| It depends on your destination. It doesn't make sense to
| get things on Mercury and bring them to Earth, but if you
| need them in space, it may make sense. Don't forget that
| you pay about 12-13 km/s of delta V to get anything from
| Earth either.
| lmilcin wrote:
| You still don't seem to understand. You need 12-13km/s to
| get to anywhere useful from Mercury. Closer to Sun than
| Earth there is only Mercury and Venus and nothing else.
|
| For example, if you wanted to build a base on Mars using
| resources that you obtained somewhere else, it would
| actually require many times more fuel to get anything
| from Mercury than it would be to get it from Earth
| surface.
| Valgrim wrote:
| It has, however, a tremendous value for building Dyson swarms
| and other megastructures.
| lmilcin wrote:
| I disagree.
|
| Tell me, how putting actual human on Mercury helps building
| a megastructure? It is not like they will be able to do
| shit while on the surface of Mercury. They would be just
| sitting idle in a single polar crater that happens to be
| shaded from Sun and have access to water. Then if you want
| to send anything to an orbit where you would want to build
| Dyson sphere you would actually have to expend more energy
| than if you tried to send it from surface of Earth. That
| makes absolutely no sense.
|
| I think these types of megastructures will be built by
| swarms of autonomous drone ships that can collectively
| gather, transform and deliver resources, use gathered
| resources to produce more drones and use the rest of
| resources to build whatever megastructure has been
| programmed in.
| bregma wrote:
| We do these things, and the other things, not because they
| are easy but because they are hard.
| lmilcin wrote:
| No, there are very few people who actually do this.
|
| People collectively do hard things when they are
| profitable.
|
| Profitability here in most broad sense possible. US did not
| send men to Moon because it was hard. It was done because
| US was in a race with USSR and winning that race was
| _profitable_ to US.
|
| Having public opinion excited about some goal can be
| profitable, too.
|
| If you don't believe, think about it: why has Apollo
| program been stopped? Because people got used to it and
| there was nothing further to prove -- further sanding
| people to Moon after US has demonstrated it can do it
| repeatedly was extremely expensive but there were no longer
| any significant profits from it.
|
| So while it was still _hard_ it actually became
| _unprofitable_ to continue to do so.
|
| If it was _hard_ that caused US to send people to Moon,
| they would not stop sending people, they would be sending
| more, build base on Moon, etc.
| pengaru wrote:
| This is cool and all, but why am I looking at black and white
| photos in 2021 sent from something launched in 2018?
| Fronzie wrote:
| Because it's a scientific instrument and there's surprisingly
| little science value in capturing the other visible-light
| wavelengths.
| skywal_l wrote:
| Indeed but there is a great marketing value though. And these
| missions rely on being marketed to the public for continued
| funding.
| SiempreViernes wrote:
| ESA funding isn't really politicised that way since it's a
| international organisation and no single politician can get
| their names on things.
| adolph wrote:
| _All Member States contribute to these programmes on a
| scale based on their Gross National Product (GNP). The
| other programmes, known as 'optional', are only of
| interest to some Member States, who are free to decide on
| their level of involvement._
|
| https://www.esa.int/About_Us/Corporate_news/Funding
| dotancohen wrote:
| Good thing that Giuseppe Colombo wasn't a politician!
| bregma wrote:
| They could probably get more funding if they reduced the
| amount of science the probes do so they could insert sell
| and insert advertizing into the data stream.
| guntars wrote:
| Yet there's a fantastic PR and public value. The resolution
| is also only 1024x1024.
| pengaru wrote:
| I'm more forgiving on the resolution front, my assumption
| is space isn't the greatest place for a very high density
| sensor. Historically it's been discouraged to bring digital
| cameras on planes without shielding since the sensors get
| damaged cells.
|
| But why they're not just sticking an array of sensors
| everywhere they've got the b&w sensor, with fixed color
| filters in front of them, escapes me. Even smartphones are
| starting to look like insect eyes with the number of lenses
| in front of dedicated sensors. You'd also get the advantage
| of some redundancy.
| wumpus wrote:
| How much money do you want them to spend to do it your
| way, instead of doing what's needed to maximize science?
| bregma wrote:
| I guess the problem would turn into one of getting a good
| WiFi signal 90 million miles from the nearest AP.
| dylan604 wrote:
| They just need to build a StarLink-esque mission that
| drops off repeaters every million miles or so. You'll
| need at least platinum status to get access to the wifi ,
| otherwise it will be $30/hour. We know you have choices
| when you fly to Mercury, so we thank you for choosing
| BepiColombo Spacelines.
| petschge wrote:
| Starlink barely works over a few hundred kilometers.
| Thanks to the inverse square law doing it over a few
| million kilometers is about 100 million times harder.
| [deleted]
| dylan604 wrote:
| Take things literal too much? Starlink-esque. Like
| Starlink, but different. Line of site with laser beams.
| Pew Pew!!!
|
| Also, shocked context clues from the rest of the comment
| made you feel the whole thing was not tongue-in-cheek.
| SiempreViernes wrote:
| It's a navigation camera, not output from any main instrument
| so it doesn't come with a filter wheel. The importance factor
| is having very good linear response to incoming light, not
| making good phone backgrounds.
| stiller wrote:
| The images were taken using the monitoring cameras:
|
| https://www.esa.int/ESA_Multimedia/Images/2018/10/BepiColomb...
|
| Images using primary instruments will follow when it reaches
| orbit in 2025.
| m4rtink wrote:
| Does the surface of Mercury actually show any perceptible color
| or is it just basically grayscale like the Moon ?
| xioxox wrote:
| BepiColombo has an X-ray telescope on board which will
| measure the X-ray colours of the planet from X-ray
| fluorescence. This will be interesting, as it will enable the
| composition of the surface to be measured down to 10 km
| scales [1].
|
| [1]
| https://link.springer.com/article/10.1007/s11214-020-00750-2
| ojosilva wrote:
| It's even greyer than the Moon apparently. Unless this
| mission finds an active volcano, which I doubt it will, or
| some other colorful feature hidden from the previous
| missions, I think that's pretty much it, nothing but shades
| of grey.
|
| https://photojournal.jpl.nasa.gov/targetFamily/Mercury
| Tepix wrote:
| It has some subdued colours such as brown and light blue.
| Here's a previous NASA image:
|
| https://apod.nasa.gov/apod/ap110331.html
|
| Here's an image with exaggerated colours:
|
| https://apod.nasa.gov/apod/ap110616.html
| adrian_b wrote:
| The most abundant minerals in rocks in the solar system are
| white oxides, except for the iron(II) and manganese oxides,
| which are blackish.
|
| So most rocks are gray, unless they have been exposed to
| oxygen, which converts the black iron oxide into red iron
| oxide, in which case the rocks turn from some gray shade to
| some brown shade.
|
| Where there has been water, the water could have been
| dissociated by light, providing oxygen for the change of
| color. In the absence of water, there are few chances for
| anything else that could change the color of the rocks from
| gray.
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