[HN Gopher] Voyager 1 hears the hush of interstellar plasma
___________________________________________________________________
Voyager 1 hears the hush of interstellar plasma
Author : sohkamyung
Score : 266 points
Date : 2021-05-11 02:46 UTC (20 hours ago)
(HTM) web link (astronomycommunity.nature.com)
(TXT) w3m dump (astronomycommunity.nature.com)
| kuu wrote:
| Related: https://xkcd.com/1189/
| acidburnNSA wrote:
| It's pretty wild that this probe, launched 44 years ago (1977)
| and now well beyond the solar system, can still take novel
| measurements and transmit information back. At that range, our
| sun looks roughly like any other star. The nuclear radioisotopic
| thermal generator really is an incredible power source for this
| kind of application. Some info on the current design here [1].
|
| [1] https://mars.nasa.gov/internal_resources/788/
| ssheth wrote:
| One of the most important parts of the Voyager is apparently a
| little motor that rotates every 192 seconds to take 360 degree
| readings of the sky. Each rotation is called a "step" in their
| lingo .. they built it to run a few thousand steps (or about
| 4-5 years). And that little motor has now run over 5 _million_
| steps over 48 years... and is still running.
|
| More at
| https://www.nature.com/news/2008/080702/full/454024a.html
| mjgs wrote:
| Its so cool that the entire solar system has a sort of ozone
| layer (the heliopause), I also really like the diagram that
| shows how each craft is travelling in different directions.
|
| I think we should have a new mission, send out huge amounts of
| tiny crafts in all directions at the same time, to get a sort
| of Google street view of our solar system and interstellar
| space. I bet we could create crafts with modern tech that where
| tiny and much less expensive that the original pioneer and
| voyager crafts.
| Denvercoder9 wrote:
| _> I bet we could create crafts with modern tech that where
| tiny and much less expensive that the original pioneer and
| voyager crafts._
|
| It's harder than you'd expect. At that distance solar panels
| are essentially useless, so you do need nuclear power, and
| you're continuously exposed to cosmic rays, so you need
| radiation-hardened electronics. Both of these drive up the
| cost. The Voyagers also had the the outer planets in
| alignment to give it a gravity assist, so if you want to get
| there on the same time scales you'll need a more powerful
| rocket as well.
| mjgs wrote:
| I read somewhere that sending very small spacecraft to far
| away places was something that was being considered.
| Unfortunately I don't remember the details. We just need an
| artificial gravity machine.
| TheCondor wrote:
| Breakthrough starshot?
| https://en.wikipedia.org/wiki/Breakthrough_Starshot
| Chris2048 wrote:
| Given the crazy high amount of laser power this requires,
| maybe placing a satellite close to the sun, and having it
| focus solar radiation, would be better than an earth
| based laser grid?
| mjgs wrote:
| Tiny spacecrafts and sails with lasers. Yeah pretty sure
| that was it. Such a cool idea, and it would only take 30
| years, which means a lot of us will still be alive to see
| it. Imagine seeing actual closeup pictures of "earth 2".
|
| Anyway if they used the same technology, but sent
| spacecraft out into space from locations all around the
| Earth at the same time, then we could gather data as this
| fleet headed into deep space.
|
| Like one of those big planet explosions in science
| fiction movies, but instead of an explosion, just tiny
| space crafts.
| f6v wrote:
| That might be our best bet to get to other systems. But
| it's still pretty much a fantasy. The engineering
| challenges behind that project just seem insurmountable
| unless we work on it as a planet, not just NASA, ESA,
| Roscosmos, etc.
| mjgs wrote:
| It doesn't sound that hard, it's just laser kites. I bet
| Elon could do it.
| Denvercoder9 wrote:
| Apart from the insane amount of power required to use
| lasers as propulsion in this way, they also require a
| camera, computer, interstellar communications system and
| nuclear power source within a mass budget of a few grams.
| It's complete science fiction.
| mjgs wrote:
| Literally everything in this area starts out as science
| fiction. I think the general idea of sending lots of
| small craft is a good idea. It would be great to hear
| from the people building these things which parts are not
| possible currently.
| Chris2048 wrote:
| > you do need nuclear power, and you're continuously
| exposed to cosmic rays
|
| silly question: can CRs be harnessed for power?
| reaperducer wrote:
| _Google street view of our solar system_
|
| Has anyone ever updated Commodore's Visible Solar System?
| Very inspiring.
|
| https://www.lemon64.com/?mainurl=https%3A//www.lemon64.com/g.
| ..
| pantulis wrote:
| I had that on my Vic20.
|
| https://www.vic-20.it/visible-solar-sistem-1930/
| throwaway3699 wrote:
| Street view in space? I think you might be underestimating
| just how empty the solar system is.
| louthy wrote:
| So it should be quite easy to build.
|
| "Oh, it's all black here too" ;)
| Kye wrote:
| Maybe it's like Star Trek and space is full of anomalies
| even 24th century sensors miss.
| mjgs wrote:
| lol
| mjgs wrote:
| Of course it's not exactly like street view!
|
| But it is a sort of map, ok probably Google maps rather
| than street view :)
| feintruled wrote:
| The Gaia probe is doing something a little like this to
| create a full 3D star map. It rotates as it goes and uses
| parallax to measure the distance and motion between stars
| exactly.
|
| https://en.wikipedia.org/wiki/Gaia_(spacecraft)
| niceairport wrote:
| Curious as to how long does it take for the transmission to
| reach earth. Where can I learn that?
| dweekly wrote:
| 21h https://voyager.jpl.nasa.gov/mission/status/
| niceairport wrote:
| I can't say I'm surprised, but it's still pretty crazy to
| think about that it took us 44 years to get an object to a
| place it takes light less than 24 hours to get to. It feels
| both pretty far and also not far at all at the same time.
| amatecha wrote:
| Yeah, I had this reaction of like "yeah, only 21 hours?
| that's not too long"... Then it occurred to me, it's 21
| hours at the _speed of light_, something we generally
| consider effectively "instant" here on Earth. Pretty
| fascinating stuff. I'm really happy to hear we're still
| getting transmissions back from Voyager 1 - from nearly
| 23 billion kilometers away, for that matter!
|
| Also really interesting is the Voyager FAQ, even from the
| first question (about whether the cameras could be turned
| back on). "Mission managers removed the software from
| both spacecraft that controls the camera. The computers
| on the ground that understand the software and analyze
| the images do not exist anymore."
|
| https://voyager.jpl.nasa.gov/frequently-asked-questions/
| wongarsu wrote:
| > something we generally consider effectively "instant"
|
| We are in one of the very few professions where the speed
| of light is considered annoyingly slow. Just three days
| ago there was a thread of people lamenting that the
| closest Hetzner datacenter is about 50 light-milliseconds
| away
| pflanze wrote:
| I don't know enough to say, but it wouldn't surprise me
| if our speed of thinking (and perhaps also time in
| general) is indirectly tied to the speed of light;
| meaning, if the speed of light were faster, we'd be
| thinking faster, and thus the round trip speed to Hetzner
| would appear just as annoying. I'll be happy to be
| corrected.
| Chris2048 wrote:
| Given the distances involved, here's lightspeed travel
| from the sun: https://digg.com/video/light-speed-solar-
| system-travel
| kzrdude wrote:
| I think new horizons is much faster, and will catch up.
| Still the same order of magnitude though
| jonas21 wrote:
| Wikipedia disagrees:
|
| > Provided Voyager 1 does not collide with anything and
| is not retrieved, the New Horizons space probe will never
| pass it, despite being launched from Earth at a higher
| speed than either Voyager spacecraft. The Voyager
| spacecraft benefited from multiple planetary flybys to
| increase their heliocentric velocities, whereas New
| Horizons received only a single such boost, from its
| Jupiter flyby. As of 2018, New Horizons is traveling at
| about 14 km/s, 3 km/s slower than Voyager 1, and is still
| slowing down.
| kzrdude wrote:
| Oh, cool
| wartijn_ wrote:
| Not according to this stack exchange answer[0]. It quotes
| a page from John Hopkins University, although that source
| page doesn't seem to exist anymore.
|
| > Though New Horizons will also reach 100 AU, it will
| never pass Voyager 1, because Voyager was boosted by
| multiple gravity assists that make its speed faster than
| New Horizons will travel. Voyager 1 is escaping the solar
| system at 17 kilometers per second. When New Horizons
| reaches that same distance 32 years from now, propelled
| by a single planetary swingby, it will be moving about 13
| kilometers per second
|
| [0] https://space.stackexchange.com/questions/3520/when-
| will-new...
| kevbin wrote:
| Thanks for the that link. I just spent an hour in the Eyes
| on the Solar System web app and listening to Carl Sagan wax
| poetic about our Voyagers:
| https://www.youtube.com/watch?v=H92iCnecYGQ
|
| "...and far from home, untouched by these remote events,
| the Voyagers, bearing the memories of a world that is no
| more, will fly on."--C. Sagan
| celias wrote:
| The one-way light times are at the bottom of
| https://voyager.jpl.nasa.gov roughly 17.5 hours for Voyager2
| and 21 hours for Voyager 1
| holoduke wrote:
| Just About 1200 times longer and it approached the same
| distance as our nearest star at 4 ly
| wongarsu wrote:
| If we started pursuing nuclear pulse propulsion we could
| have our first probe arrive in the next star system in a
| hundred years or so, and eventually get the travel time
| closer to 40 years.
| techrat wrote:
| If?
|
| Theoretical is still theoretical. We have no functioning
| propulsion that can exceed what the probes are currently
| travelling at.
| wongarsu wrote:
| At least for something like Project Orion, all the
| individual components are either verified in prototypes
| or proven technology. We have existing stockpiles of
| nuclear bombs. Propelling a craft by exploding something
| behind it is demonstrated in smaller prototypes with TNT.
| We know how to do radiation shielding, we know how to do
| shock absorbers.
|
| Or course combining technologies in a new way comes with
| lots of engineering challenges, but it's a smaller leap
| in technology than e.g. the first moon landing.
| dweekly wrote:
| The energy density of nuclear batteries is astounding. Per the
| linked spec sheet, at 2.8W/kg and 17y mission duration, that's
| about 417,000Wh/kg. By comparison a lithium ion battery has
| 250Wh/kg.
| acidburnNSA wrote:
| Nuclear fission reactors are even crazier. With breeding you
| get 22,500,000,000 Wh/kg. Good old E=MC^2.
| dheera wrote:
| _Technically_ all batteries are E=mc^2, it 's just that
| nuclear fission converts more of the mass, but still, not
| all of it.
|
| Lithium batteries do get ever so slightly heavier when
| charged, but it's basically undetectable.
| kuprel wrote:
| How do lithium ion batteries convert mass to energy?
| dheera wrote:
| The principle of E=mc^2 is of mass-energy equivalence.
| Any form of stored energy has mass, including the binding
| energy between atoms in a molecule, and lithium ions
| convert those chemical bonds to electric currents when a
| load is applied.
|
| The mass associated with those chemical bonds is
| miniscule compared to the protons, electrons, and
| neutrons, but it is not zero.
| ben_w wrote:
| All (confined?) energy is equivalent to mass, even when
| that mass isn't in the form of elections and quarks.
| samplatt wrote:
| There's a _really good_ joke about Ferengi political
| situations here, but I 'm no economist.
| ben_w wrote:
| I think quark jokes are a bit cheesy myself. ;)
| 12ian34 wrote:
| I find them strange and charming
| mynegation wrote:
| Hey it is not Reddit, but at least these are not off-
| color jokes.
| varjag wrote:
| Fission is not anywhere near E=MC^2. That would be
| matter/antimatter annihilation.
| willis936 wrote:
| It is E=MC^2 though. 0.1% of the mass is converted into
| energy.
| varjag wrote:
| No, it's E=(0.001M)C^2
| willis936 wrote:
| That is absurd. It is E=MC^2 where M is 0.1% of the total
| mass of the reactants.
|
| 100% of the mass difference is converted into energy.
| varjag wrote:
| The GP was talking in relation to W/Kg, and the output
| per Kg is definitely not e=mc^2. It helps reading things
| in the context.
| StavrosK wrote:
| You are correct, though it would help to clarify that
| you're correcting the GP on the "per kilo" part, and not
| the "energy" part.
|
| I agree, if you're deploying 1 kg of fissile material,
| only 0.1% of that will be converted to energy. We should
| talk about energy per mass of fissile material, not
| energy per mass of "mass difference".
| whatshisface wrote:
| Windup toy cars are also E=mc^2.
| prewett wrote:
| E = mc^2 implies that mass (m) is being converted to
| energy (E), and a windup toy car is definitely not
| converting mass to energy. Windup cars get their energy
| from torsional springs, which are E = (1/2) k theta^2.
| whatshisface wrote:
| > _and a windup toy car is definitely not converting mass
| to energy_
|
| Ah, but it is. E=mc^2 is always true in the reference
| frame where the object is stationary. (We assume that we
| are co-moving with the windup car.) A spring under
| torsion is heavier than an unwound spring.
| Chris2048 wrote:
| > A spring under torsion is heavier than an unwound
| spring
|
| Does it have more (invariant) mass?
| whatshisface wrote:
| Yes.
| The_rationalist wrote:
| So with a nuclear fission reactor NASA could make an
| immortal space probe! It's very sad that this isn't a
| project.
| f00zz wrote:
| The Russians have a few of those:
| https://en.wikipedia.org/wiki/BES-5
| dheera wrote:
| Nuclear fission reactors have a lot of moving parts, and
| creating something that lasts 50 years without one of
| those moving parts failing, unmanned, and subject to the
| harshness of space, isn't trivial.
|
| Nuclear batteries are extremely reliable though, as they
| are fully solid state. A Pu-238 battery can emit useful
| amounts of power for upwards of a century, and there is
| virtually nothing to break.
| sundvor wrote:
| It appears to be holding up well at 27 years past the age
| spec too. It is astonishing how something sent out when I was
| a toddler is still working till this date; kudos to the
| engineers.
| windy_willow wrote:
| I am so impresses that this device is still actually able to do
| so much after so long... I really hope that the current space
| probes and rovers do just as well if not better.
| tablespoon wrote:
| > It's pretty wild that this probe, launched 44 years ago
| (1977) and now well beyond the solar system, can still take
| novel measurements and transmit information back.
|
| Through (according to Wikipedia) the party might end in just a
| few years: https://en.wikipedia.org/wiki/Voyager_1:
|
| > Voyager 1's extended mission is expected to continue until
| about 2025, when its radioisotope thermoelectric generators
| (RTGs) will no longer supply enough electric power to operate
| its scientific instruments.
| The_rationalist wrote:
| What about voyager 2 lifetime ? Humanity hasn't sent any
| probe having an extra-solar system target since 1977?? If so,
| this is extremely sad and distant space exploration will die
| and 50 years will be lost. I attribute this mediocrity to the
| anti nuclear/RTG lobby at NASA
| csunbird wrote:
| We haven't sent another probe, not because of anti nuclear
| lobby, but because of there was an unique event of planets
| being nearly on a line around 1970, which allowed NASA to
| plot a series of gravity assists, instead of one or two,
| that allowed gaining immense amount of free velocity.
|
| Sun's gravity well is so immense that escaping it requires
| a very, very large amount of energy. I am not sure if it
| could be done with conventional rockets with current
| technology, without multiple gravity assists.
|
| Edit: As the child comment says, it seems to be possible
| with current technology. It is very exciting!
| foobarian wrote:
| I'm puzzled by the requirement for an alignment. It seems
| one could gravity assist in arbitrary directions though
| it might take longer. But should still end up with a
| similar energy gain.
| teraflop wrote:
| > I am not sure if it could be done with conventional
| rockets with current technology, without multiple gravity
| assists.
|
| Yes, it can. New Horizons is escaping the solar system
| only a little bit slower than the Voyager probes, and it
| was already on an escape trajectory before its single
| Jupiter gravity assist.
| throwaway894345 wrote:
| I wonder what hope we have for making probes that will
| last longer (i.e., "do science even deeper in space")
| than Voyager 1, Voyager 2, and New Horizons.
| Specifically, whether we can make RTGs or other power
| sources that last longer and/or scientific instruments
| that operate with lower power (without compromising on
| quality or quantity of observations). Maybe there just
| isn't much science to do beyond the Kuiper Belt (or
| rather, getting 50 years beyond the Kuiper Belt doesn't
| improve science much more than making the same
| observations from the KB itself due to the vastness of
| space)?
| ProAm wrote:
| New Horizons is quite a bit slower and will never
| overtake the Voyager probes distance wise.
| phist_mcgee wrote:
| Slow down with the over-dramatisation buddy. Nothing has
| been lost, interstellar exploration hasn't died, and I am
| not exactly sure why an anti-nuclear lobby at NASA has
| anything to do with either of these things.
| phreeza wrote:
| The trajectory for the Voyager probes was made possible by
| the alignment of Earth, Jupiter, Saturn, Uranus and
| Neptune. A similar alignment will not occur again until the
| middle of the 22nd century.
| throwawayboise wrote:
| Handy coincidence that the last alignment happened just
| as our technology reached the point where we could take
| advantage of it.
| Denvercoder9 wrote:
| _> Humanity hasn 't sent any probe having an extra-solar
| system target since 1977??_
|
| The Voyagers didn't have an extrasolar target either, they
| were meant to visit the outer planets. If we're looking at
| probes that leave the solar system after their original
| mission, we launched New Horizons in 2006 to Pluto, and
| it's currently in the Kuiper Belt on its way to leave the
| solar system.
| fogihujy wrote:
| Just to add to that: NH is on it's way out of the system
| now, after 15 years, and it should have another 15-20
| years left in it's RTG.
|
| Meanwhile, there are actual interstellar probes being
| planned, in addition to several missions to the outer
| solar system (and which could end up in interstellar
| space afterwards).
|
| And there's a ton of missions planned for the inner
| regions of the Solar system -- space exploration is still
| a thing and there's a lot of exciting things happening.
| f6v wrote:
| I wonder why don't we send more probes like that in every
| direction by dozens?
| dredmorbius wrote:
| There's not much, in every direction, for a long ways.
|
| It makes more sense, generally, to send probes to where
| things (planets, moons, dwarf planets, asteroids, comets)
| are, that we can reach in reasonable time (years, possibly a
| decade or more for outer targets).
|
| "Every direction" just takes you to deep space. And that's
| not going to be particularly illuminating, though a few such
| probes (say, a high- or low-solar plane one) might be
| interesting.
| f6v wrote:
| Oort cloud is still not confirmed, right? I get that it
| might be incredibly sparse, but isn't there anything to
| study there?
| dredmorbius wrote:
| Oort is (mostly) in the solar plane AFAIU, and there's
| every reason to use gravity assist to get there. I don't
| know that any specific objects are known, and getting
| into an Oort-observing orbit might be challenging.
| Otherwise, yesm it's sparse and arbitrary flybys would
| likely miss anything interesting.
|
| Spraying random probes in all directions makes lttle
| sense.
|
| Voyager 1 won't reach the Oort Cloud, if it in fact
| exists, for another three centuries.
| throwaway894345 wrote:
| I was thinking it would be interesting to send a stream of
| them out in one direction (or many streams) with the idea
| that they could serve as a relay/mesh network, allowing us to
| communicate with the probes (and vice versa) for longer. Not
| sure how valuable that would be scientifically.
| asaddhamani wrote:
| It's now 22 Billion km away from Earth. Amazing.
| qwertox wrote:
| Thanks. Your comment sent me to Wikipedia, where I found this
| related snippet:
|
| > In the year 2000, 23 years after production, the radioactive
| material inside the RTG had decreased in power by 16.6%, i.e.
| providing 83.4% of its initial output; starting with a capacity
| of 470 W, after this length of time it would have a capacity of
| only 392 W. A related loss of power in the Voyager RTGs is the
| degrading properties of the bi-metallic thermocouples used to
| convert thermal energy into electrical energy; the RTGs were
| working at about 67% of their total original capacity instead
| of the expected 83.4%. By the beginning of 2001, the power
| generated by the Voyager RTGs had dropped to 315 W for Voyager
| 1.
|
| There's also a nice picture of one deployed on the moon. The
| dust on the moon's surface looks spectacular in that picture.
|
| https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_ge...
| tutfbhuf wrote:
| How much Watt do they have now 20 years later in 2021?
| chias wrote:
| I can give you half an answer and speculation on the other
| half.
|
| Given that radioisotopes decay with a halflife pattern, I
| would expect that you'd see a 16.6% drop in capacity every
| 23 years. So something like: 1977: 100%
| (470 W) 2000: 83.4% (392 W) 2023: 69.6%
| (327 W)
|
| To get a full answer, you'd need to know how the
| thermocouples degrade. Under the (completely
| unsubstantiated) assumption that they degrade linearly,
| that's about a 20% efficiency degradation per 23 years:
| 1977: 100% isotope * 100% coupling efficiency -> 470 W
| (100% of capacity) 2000: 83.4% isotope * 80%
| coupling efficiency -> 314 W (67% of capacity)
| 2023: 69.6% isotope * 60% coupling efficiency -> 196 W (41%
| of capacity)
|
| I suspect the thermocouple efficiency degradation is very
| much non-linear -- or rather, I have no reason to actually
| expect it to be linear -- so the second half of the above
| is a total SWAG, but maybe gives you a rough idea :)
| st_goliath wrote:
| > There's also a nice picture of one deployed on the moon.
|
| That was also one of the many issues that cropped up during
| Apollo 13. They too had an RTG on board that was supposed to
| stay on the moon[1].
|
| According to the book "Lost Moon" by Lovell and Kluger, a
| potential explosion of the Saturn V during launch was
| accounted/planned for, but the RTG "coming home" together
| with the LEM wasn't.
|
| IMO the book was a bit hazy on how that situation was
| addressed exactly, but according to Wikipedia that RTG is
| currently resting somewhere deep in the Pacific[2].
|
| Also an interesting read on that topic is the SNAP program
| itself that developed the technology in the first place, even
| shot entire mini-nuclear-reactors into earth orbit[3] and
| resulted in some stereotypical 1960s nuclear safety
| shenanigans/mishaps during testing[4][5].
|
| [1] https://en.wikipedia.org/wiki/Apollo_13#Experiments_and_s
| cie...
|
| [2] https://en.wikipedia.org/wiki/Apollo_13#Reentry_and_splas
| hdo...
|
| [3] https://en.wikipedia.org/wiki/Systems_for_Nuclear_Auxilia
| ry_...
|
| [4] https://en.wikipedia.org/wiki/SNAP-10A#Safety
|
| [5] https://en.wikipedia.org/wiki/Systems_for_Nuclear_Auxilia
| ry_...
| divbzero wrote:
| It's also wild to compare:
|
| - how far Voyager 1 has already traveled ~150 AU or ~0.002 ly
| [1]
|
| - how much farther it could go in 40,000 years ~1,000,000 AU or
| ~17 ly [2] [3]
|
| - the visible diameter of our Milky Way ~6,000,000,000 AU or
| ~100,000 ly [4]
|
| [1]: https://voyager.jpl.nasa.gov/mission/status/
|
| [2]: https://voyager.jpl.nasa.gov/mission/interstellar-mission/
|
| [3]: https://en.wikipedia.org/wiki/Gliese_445
|
| [4]: https://en.wikipedia.org/wiki/Milky_Way
| tommi wrote:
| Could we realistically accelerate a space probe to faster
| speeds than what Voyagers and New Horizons are currently
| doing?
| pwned1 wrote:
| As a ham radio enthusiast I find this sort of article
| fascinating, from the actual frequencies detected to the fact
| that even Voyager suffers from RFI. :)
| tablespoon wrote:
| > One of our chief goals was to apply the power of signal
| processing to search for weaker signals in the PWS data, which
| maybe, just maybe, were hiding between and behind the bright
| plasma oscillation events that had already been discovered.
|
| So this _doesn 't_ mean that Voyager 1 has entered a new region
| with different characteristics, just that they've used signal
| processing to tease a little bit more out of the existing data.
| senbarryobama wrote:
| Soon Voyager will be another planets Ouamuamua
| gumby wrote:
| I find this tremendously thrilling, and not just for the exciting
| discoveries about the environment of the outer solar system.
|
| Somehow human spaceflight seems dull to me while I just can't get
| enough of the cool and crucial work these robots are doing on our
| behalf.
|
| Never send a human to do a robot's job, I suppose.
| artpop wrote:
| Aliens.
| robofanatic wrote:
| Are there any such probs sent in recent years with latest
| technology on it?
| 3pt14159 wrote:
| Well there is New Horizons[0], which launched in 2006 and is
| now beyond Pluto. But in terms of coolness, I really like The
| Parker Solar Probe[1] which is going closer and closer to the
| sun with a massive heat shield and at eye watering speeds. By
| 2025 it will be going 690,000 km/h (430,000 mph), or 0.064% of
| the speed of light.
|
| [0] https://en.wikipedia.org/wiki/New_Horizons
|
| [1] https://en.wikipedia.org/wiki/Parker_Solar_Probe
| 1970-01-01 wrote:
| >Who knows what discoveries still lie ahead of it?
|
| Its very likely this is the last one. The craft is simply running
| out of power and the instruments will be forced to shutdown in a
| few years. The current deep space network will lose its already
| extremely faint signal in about a decade.
| RedOrGreen wrote:
| I came to this thread a bit too late, but if you're interested in
| the actual signal that Stella found, take a look at the spectrum
| vs time on the NASA release [1] - third plot on the page, with a
| convenient slider that lets you flip back and forth to see the
| previously known plasma oscillation events and the newly
| discovered continuous signal. Notice the huge change in scale!
|
| [1] https://www.nasa.gov/feature/goddard/2021/as-nasa-s-
| voyager-...
| ilamont wrote:
| What are MAG rolls cited in video?
| wolverine876 wrote:
| > While I was busy learning the undergraduate physics curriculum,
| Voyager 1 was treading through the interstellar medium and
| revealing in stark detail how interstellar plasma and the solar
| wind collide and interact across a boundary layer called the
| heliopause, where they engage in a massive pressure-balancing act
| that shields our heliosphere from the great beyond.
|
| I thought Voyager 1 was out in interstellar space for awhile now,
| beyond the heliopause, heliosphere, etc. ?
|
| I'll also note,
|
| > Almost 11 years ago, Voyager 1 crossed an unprecedented
| boundary: it became the first human-made object to enter
| interstellar space. I was just a high-school student at the time,
| oblivious to the milestone ...
|
| That's no excuse! :)
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