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Galileo's Flyby of Almathea

An anonymous reader writes "The spectacular Galileo flybys of Jupiter, Europa and Io are largely credited with the discovery of frozen water ice and some of the earliest examples of non-solar (tidal) heating anywhere in our solar system. For the next 10 days, Galileo scientists are preparing for their next target: probing one of Jupiter's moons, Almathea, at the close-up range of 100 miles. Almathea is one of the most unusual moons in the solar system, because it gives off more heat than it receives from the Sun."

84 of 169 comments (clear)

  1. frozen water ice? by deaton · · Score: 4, Funny

    is that anything like unfrozen ice water?

    1. Re:frozen water ice? by Alain+Williams · · Score: 4, Informative

      The point is that 'ice' can be made from all sorts of liquids - water is just one of them.

    2. Re:frozen water ice? by comic-not · · Score: 4, Informative

      Well, ices can exist in the crystalline or amorphous phase. E.g. the water ice inside cometary nuclei is in amorphous form, and one can argue that it is technically not frozen, because it has originally been built from such tiny particles that there hasn't been a meaningful macrostate (BTW, did you ever create amorphous sulphur in the chemistry class?) to call it such. When amorphous ice is heated, it turns to the 'normal', crystalline phase, which more closely resembles our concept of 'frozen'. I don't know, however, whether the original poster tried to express this distinction.

      --
      Existence usually comes as a surprise (Idem)
    3. Re:frozen water ice? by comic-not · · Score: 2, Informative

      Ever tasted dry ice cream? I thought not. Dry ice is carbon dioxide ice. In planetary physics, all volatile compounds in solid form are known as ices.

      --
      Existence usually comes as a surprise (Idem)
    4. Re:frozen water ice? by evilpenguin · · Score: 2

      I dunno. Someone who has been on /. for >5 years and has only made 30 comments might be very smart indeed. People who talk a lot may seem smart, but... (This is from a guy who talks all the time, BTW)

    5. Re:frozen water ice? by comic-not · · Score: 2, Informative

      "dry ice" is marketing term and has NOTHING to do with physics.

      Indeed, I tried to stay on the same colloquial level as the previous poster. But I happen to be a space scientist with a Ph.D. in physics, and my field of study is, surprisingly enough, comets. And when planetary scientists discuss these things, they say water ice, methane ice, CO2 ice, et.c., to make it clear what they are talking about, since, as I said, all volatiles in solid form are called ices.

      --
      Existence usually comes as a surprise (Idem)
  2. Gives out more heat that it recieves. by Anonymous Coward · · Score: 5, Funny

    Lisa, In this house we obey the laws of thermodynamics.

    Yes i know there are other explainations

    1. Re:Gives out more heat that it recieves. by TooCynical · · Score: 3, Interesting

      Yet another law to disobey... http://news.bbc.co.uk/1/hi/sci/tech/2135779.stm

      --
      Homer: Facts are meaningless, you can use facts to prove anything that's remotely true!
    2. Re:Gives out more heat that it recieves. by verag · · Score: 5, Informative
      The planet itself does this as well... "...Jupiter radiates nearly twice as much heat as it receives from the Sun." Found here

      Jupiter is by far the most interesting planet (with it's moons) to me, other than the Earth. More information as well as pictures can be found on NASA's site for the planet itself.

    3. Re:Gives out more heat that it recieves. by Jugalator · · Score: 4, Interesting

      I think at least Io was so volcanic and active because of the extreme "tidal waves" from Jupiter. The "waves" are, due to the huge gravitation of Jupiter, so strong they pull solid matter and this of course cause quite a bit of friction. And friction cause heat. Not really surprising, since such a small object as our Moon does funny things to our seas. :-)

      Anyway, to my point, perhaps the same applies to Amalthea?

      --
      Beware: In C++, your friends can see your privates!
    4. Re:Gives out more heat that it recieves. by evilpenguin · · Score: 2

      Our moon pulls earth's solid surface out of shape too. The amount of motion is much smaller than the ocean's but it is not inconsiderable. Can anyone closer to their Geology 101 class or Astronomy 101 class remember how many inches the crust moves tidally? (Okay, cm's?)

    5. Re:Gives out more heat that it recieves. by at_18 · · Score: 2

      The moon is about 1/4 of Earth's diameter, but only 1/81 of its mass (in other words, it's really a huge moon for our planet).

      In an absolute sense, it's quite big: its size is similar to that of the biggest Jupiter satellites (Io, Europa, Ganimede, Callisto).

      In the solar systems, there are over 50 moons, and our Moon is in the top 5 or so.

    6. Re:Gives out more heat that it recieves. by mpe · · Score: 3, Insightful

      I think at least Io was so volcanic and active because of the extreme "tidal waves" from Jupiter. The "waves" are, due to the huge gravitation of Jupiter, so strong they pull solid matter and this of course cause quite a bit of friction. And friction cause heat. Not really surprising, since such a small object as our Moon does funny things to our seas. :-)

      IIRC Io being heated is part of an interaction with the other Jovian moons. What happens is that a moon generating tides also transfers energy to the moon, so that it moves away from the planet it orbits. This is what happens here on Earth.
      With Io the interaction of the other large moons keeps in in orbit, so the energy shows up as vulcanism.

  3. Almathea must be overclocked by phpinfo() · · Score: 3, Funny

    Doesn't anyone make a good cooling system for moons?

  4. I'm a little Confused by ksplatter · · Score: 3, Funny

    I thought this Galileo guy died a long time ago. And with him being so busy with Astronomy how did he ever find the time to learn how to Fly?

    Boy you sure learn something new everyday reading Slashdot!

    1. Re:I'm a little Confused by apt142 · · Score: 5, Funny

      Haven't you read the Hitchhiker's Guide? Flying is easy. All you have to do is throw yourself at the ground and miss.

  5. heat generator by scrod98 · · Score: 5, Funny
    because it gives off more heat than it receives from the Sun

    And NASA releases a picture of the Intel Inside logo on the surface...

    --
    LETS DECOMPOSE & ENJOY ASSEMBLING
    1. Re:heat generator by JimPooley · · Score: 2

      NASA releases a picture of the Intel Inside logo on the surface...

      AMD, surely...

      --

      "Information wants to be paid"
    2. Re:heat generator by teamhasnoi · · Score: 2

      Old Navy will do a commercial there next.

  6. what are they hoping to find? by Transient0 · · Score: 4, Funny

    a civilization of alien potheads who have hotboxed an entire atmosphere?

    or maybe the worlds biggest overclocked processor.

    I can't think of any other reasonable theory to account for this moon radiating so much heat.

    1. Re:what are they hoping to find? by isorox · · Score: 3, Funny

      I can't think of any other reasonable theory to account for this moon radiating so much heat.

      Perhaps the 65,000 processors in IBM's new computer?

    2. Re:what are they hoping to find? by DjMd · · Score: 3, Funny

      Geothermal/volcanic comes to mind?
      Doesn't Io's volcanic activity come from jupiter's pull?

      That would be my first guess...



      That or the monolith left the hot plate pluged in...

      --
      DJMD - The fourth man - Planetary
  7. Earth has Moon Envy by Zech+Harvey · · Score: 5, Funny


    I mean, that's the only explanation I can come up with. Ours just...you know, sits there. We go there once, get bored and come back. So we spend our time looking at other planets' moons instead of making it back to ours. I mean really. Give our moon some lubbin'!

    --
    Zech Harvey, MCSE, MCDBA, CCNA
    1. Re:Earth has Moon Envy by edremy · · Score: 4, Interesting
      Nah. Ours is the biggest, at least in relation to our size. (Forget Pluto+Charon; they're just comets that took a wrong turn.)

      It's not the number, it's the size, baby.

      (And in seriousness, there's a fair number of theories that think life would not have come about without the large tides raised by the moon.)

      --
      "Seven Deadly Sins? I thought it was a to-do list!"
  8. Nice rendered pictures by Dark+Lord+Seth · · Score: 5, Informative

    For those of us who aren't very much at home in astronomy and it's terms and who just want to see (relatively) pretty pictures; Celestia also has Almathea available for your viewing pleasure, along with allot of different stuff in our solar system and even beyond there. Besides, it's a pretty proggy... :)

  9. Almathea? by CommandNotFound · · Score: 4, Funny

    ...isn't that the planet where they used to build luxury planets for the super-rich?

    1. Re:Almathea? by Anonymous Coward · · Score: 2, Informative

      s/Io/Europa/

    2. Re:Almathea? by JimPooley · · Score: 3, Informative

      I thought the quote was "All these worlds are yours, except Europa. Attempt no landings there" after Jupiter ignited to melt the ice...

      --

      "Information wants to be paid"
    3. Re:Almathea? by shd99004 · · Score: 2
      If I remember correctly:


      All these worlds are yours
      Except Europa
      Attempt no landing there
      Use them together
      Use them in peace

      --
      Will work for bandwidth
    4. Re:Almathea? by Tackhead · · Score: 5, Funny
      > I thought the quote was "All these worlds are yours, except Europa. Attempt no landings there"

      All these moon are belong to you.
      Except Europa. Europa are belong to us.
      You have no chance to survive, make your time.
      Move "Discovery"! For great monolith!

      Hmm, I think must've seen the Japanese translation...

    5. Re:Almathea? by ceswiedler · · Score: 2

      boy i wish i had mod points

    6. Re:Almathea? by Amazing+Quantum+Man · · Score: 2

      The last two lines are from the movie only. The first three are from the novel.

      --
      Fascism starts when the efficiency of the government becomes more important than the rights of the people.
  10. Shift the focus already by Drunken+Coward · · Score: 3, Insightful

    Spending all these resources investigation such distant objects in outer space when there is so much so close to us that we have yet to get a good view of. Walk before we run people!

    --
    Have you been stalked by Seth today?
    1. Re:Shift the focus already by Blackneto · · Score: 3, Insightful

      Um, Galileo has been orbiting Jupiter for 7 years. It's not like it's costing them a lot more to do this.
      Think and read before we post people!

      --
      Ursula Andress, Catherine Deneuve, and Charo, twice...
    2. Re:Shift the focus already by ChuckDivine · · Score: 5, Insightful

      While I strongly support looking for close in objects, it's not like it's an either/or situation. The world has lots of astronomers (and other kinds of scientists as well). We also have resources sufficient to do research into a wide variety of astronomical phenomena.

      Those of us who have actually done some political work in support of looking for earth approaching asteroids only ask for a few millions of dollars to finance such work. Focusing all of our attention on nearby objects would be foolish and wasteful in the extreme.

      --
      "Beer is proof God loves us and wants us to be happy." -- B. Franklin
  11. For those looking for Earth like planets... by MrFenty · · Score: 5, Insightful
    This sort of place is exactly the sort of reason I think, if we find life elsewhere in the universe (intelligent or otherwise) then it won't have to be on a planet that looks exactly like Earth and at roughly 1 AU from its local star. Here we have a moon that gives off heat, at a very large distance from its sun. There is no reason for us to be arrogant enough to assume that life can only exist on a place that looks identical to our place. This really bugs me, when I see people say "life can't exist there, that planet is twice Earth's distance from its star..." and rubbish like that. Aarrgghh !

    Sorry, I needed that rant.

    1. Re:For those looking for Earth like planets... by FortKnox · · Score: 4, Informative

      To continue your rant philosophically...

      We are ignorant when it comes to life. What exactly is life? We only know what life is within our world.
      Astronomers get excited at the fact that we can find water on Mars and Europa, meaning they could have life, because our knowledge of life involves water. But, as far as we know, there could be life on the moon, we just aren't looking for it correctly.
      If (or when, depending on your philosophy) we find extraterrestrial life, it will be when we aren't looking for it, IMHO.

      --
      Good quote, too many chars. Seriously, the slashdot 120 char limit sucks!
    2. Re:For those looking for Earth like planets... by mustangdavis · · Score: 3, Interesting
      We are ignorant when it comes to life. What exactly is life?


      Isn't this why there are plans to retrieve some of the upper atmosphere of Venus? There have been several articles on /. recently describing how there could be life in Venus's upper atmosphere ... just floating around, using carbon monoxide and the energy from the sun as a means of sustaining life.

      BTW: I doubt you're going to find water on a planet as hot as Venus :)

      This is why I REALLY hope there is life on Venus ... it will make everyone take a hard look at where we should be looking for life. These "aliens" won't have arms and legs as we think of them, which would also be excellent!

      But it would definately be cooler if we found something a bit more advanced than floating bacteria on Almathea, Europa or IO.

      If there was life that was slightly more advanced, it is only a matter of time before someone from N*Sync will want to take a field trip out there ...

    3. Re:For those looking for Earth like planets... by aurelian · · Score: 2, Insightful

      Planet hunters don't assume that life can only exist on earth-like planets. However they do assume that life might be more likely to be found on earth-like planets. hence it's worth looking for them.

    4. Re:For those looking for Earth like planets... by overunderunderdone · · Score: 5, Informative

      This really bugs me, when I see people say "life can't exist there, that planet is twice Earth's distance from its star..." and rubbish like that. Aarrgghh !

      If you are ranting about the "rare earth hypothesis" you should remember that the authors believe that life is MUCH more common than was previously believed. However they believe that advanced life and advanced civilizations are MUCH rarer than previously believed and do require conditions substantially similar to earths. Even you own post basically makes some of the same assumptions - you see the heat from this moon as promising because that heat is one of the prerequisites for life, the rare earth hypothesis adds additional prerequisites which must be present for *advanced* life. There are those that simply assume without thinking that life must evolve on a planet substantially similar to earth. The rare earth hypothesis arrived at pretty much the same conclusion through serious thought on the subject. They may be wrong (we simply don't have enough data) but their reasoning is sound and not based on simple prejudice or ignorance.

    5. Re:For those looking for Earth like planets... by susano_otter · · Score: 2

      Also, that "Class M" planets will be more likely to sustain human life, making their discovery not just of interest to the scientific community in a "we hope to find alien life here" kind of way, but also intensely personal to the human race in a "we hope to someday live here" kind of way.

      --

      Any sufficiently well-organized community is indistinguishable from Government.

  12. Looking at Jupiter and its moons by igotmybfg · · Score: 5, Insightful
    Two summers ago, one of my friends in University here asked me to come outside with her and look at something which she described as 'cool'. Thinking I might get some :) I went with her, and we set up a tripod and telescope and ended up watching the stars all night long. For a time we focused on Jupiter, and though I couldn't see Almathea, I did see Jupiter, Callisto, Io, Europa, and Ganymede. The thought that there was nothing (well, almost nothing) in between me and those huge, huge objects that were so very far away still sends tingling down my spine whenever I think about it. It reminds me, when I think that there is pretty much nothing left to do or discover, that there is indeed a whole universe out there, waiting for (or perhaps indifferent to) us.

    Cheers!

    1. Re:Looking at Jupiter and its moons by allanj · · Score: 5, Funny

      Well, I think I speak (type?) for all of us here - did you, in fact, get some?

      --
      Black holes are where God divided by zero
    2. Re:Looking at Jupiter and its moons by tsa · · Score: 2

      Better than sex huh?

      --

      -- Cheers!

    3. Re:Looking at Jupiter and its moons by archen · · Score: 4, Funny

      in between me and those huge, huge objects that were so very far away still sends tingling down my spine whenever I think about it.

      I think so.

    4. Re:Looking at Jupiter and its moons by vinlud · · Score: 5, Funny

      The thought that there was nothing (well, almost nothing) in between me and those huge, huge objects that were so very far away still sends tingling down my spine whenever I think about it. It reminds me, when I think that there is pretty much nothing left to do or discover, that there is indeed a whole universe out there, waiting for (or perhaps indifferent to) us.

      You're talking 'bout the girl now right?

      --
      Repeat after me: We are all individuals
    5. Re:Looking at Jupiter and its moons by cr0sh · · Score: 2
      Whether you got some or not aside, I know what you mean. When I think of things like this, the fact that we humans actually have the tech to perform such feats - probes to other planets, men on other worlds - it causes within me the same kind of reaction.

      Then tears come to my eyes...

      For I know that despite all of this, despite the facts, despite the wonder, despite the possibilities - the majority of humans do not care one way or the other about it. They would rather war, rape, pillage, and plunder to death a world which currently is the only one we have - yet they seem unable to grasp this simple concept. These same humans continue to believe in the idea of an invisible being "in the sky", a being who apparently hates other invisible beings, who insists that those invisible beings be destroyed, along with those who believe in that being, or don't believe in his being. Yet these same humans consider such concepts as the "easter bunny" and "santa claus" to be fantasy imaginings of children's fairytales.

      These people continually fight, some for their invisible men, most for more space - when with a little solidarity, and the realization that humans really do only get one life, and that death shouldn't be feared (do those who fear the consequences of a fictional afterlife wonder what came before their birth - also, if they don't remember what came before, what logic says they will know what comes after?), and that by there only being one life per each living thing, makes that life ALL THE MORE PRECIOUS. This logic doesn't destroy morality, but affirms it in a great way. With this realisation, working together to explore all of these other worlds would expand the space available for mankind, while furthering our wonder and the workings of the universe. Why does it seem so few can get these rather simple concepts?

      Perhaps we really are nothing more than "advanced animals", and really don't deserve all of what is out there..

      --
      Reason is the Path to God - Anon
    6. Re:Looking at Jupiter and its moons by SmokeSerpent · · Score: 2

      When the female friend in HS pulled me outside to "show [me] something", all I got was sex.

      Dammit!

      --
      All kings is mostly rapscallions. -Mark Twain, The Adventures of Huckleberry Finn
  13. Monolith? by alexc · · Score: 5, Funny

    Did Galileo find a Black Monolith yet?

    1. Re:Monolith? by Mr_Dyqik · · Score: 2

      It'd have to go to Saturn to find that... Japetus (or maybe Iapetus) is the place to go.

    2. Re:Monolith? by uncoveror · · Score: 2

      I'm sorry, Dave. I'm afraid I can't do that.

      --
      The Uncoveror: It's the real news.
    3. Re:Monolith? by khendron · · Score: 3, Informative

      No no no. Clarke envisioned Amalthea (a.k.a Jupiter V) as great big a spaceship, used by an extinct alien race to move to our solar system. See here.

      --
      Life is like a web application. Sometime you need cookies just to get by.
    4. Re:Monolith? by Guppy06 · · Score: 2

      "Did Galileo find a Black Monolith yet?"

      Wrong system. You'll have to look at what's in orbit around Saturn. It doesn't teleport to the Jovian system until Kubrick gets involved, and since he's now dead...

    5. Re:Monolith? by Tackhead · · Score: 2
      > Did Galileo find a Black Monolith yet?

      The sad thing is we'll never know, because for want of $100,000 - or rather, because of a bureaucratic culture at NASA - we won't be taking any pictures as we fly by it at 100 km range.

      So for anyone that wondered exactly what's in that red stuff that Io's splattered all over Amalthea's surface over the past few million years, tough. Wait for the next Jupiter probe. What's another 20-30 years, huh? But at least we've got a useless space station in a useless orbit!

    6. Re:Monolith? by Amazing+Quantum+Man · · Score: 2

      The original concept of the Star Gate was a hole in Amalthea (Jupiter V). See The Lost Worlds of 2001 for more details.

      --
      Fascism starts when the efficiency of the government becomes more important than the rights of the people.
  14. Almathea? by Kierthos · · Score: 3, Funny

    "All these are yours, save Io. Attempt no landing there."

    No problem, guv. These other moons look much more interesting.

    Kierthos

    --
    Mr. Hu is not a ninja.
  15. AmaLthea, not ALmathea by Anonymous Coward · · Score: 5, Informative

    Hell, has nobody noticed that the real name is Amalthea?
    Where are your classics!?
    She was the goat that nurtured baby Zeus = Jupiter!

  16. Earth Mark 2 by KlomDark · · Score: 2

    Isn't the extra heat because of all the other planets being built there?

    Oh wait, that's Magrathea...

  17. Amalthea by Blackneto · · Score: 5, Informative

    The Correct spelling is Amalthea.
    It says so on the JPL's website.
    Also Amalthea was a nymph that nursed Jupiter in mythology. This fits in with the naming of the other moons.
    It looks like it was only misspelled once on the astrobio site which may be the cause of the confusion.

    --
    Ursula Andress, Catherine Deneuve, and Charo, twice...
  18. More than just little green men. by Njoyda+Sauce · · Score: 3, Interesting

    Seriously, as interesting as it would be to find alien life on one of these moons, the more probable scientific interest here would be unlocking a new method of heat creation.

    In the future as we attempt to colonize anything other than earth, we might find it's a bit chilly out there. Generating long-term, sustaining heat on a planetary scale without a nearby sun would be a feat indeed! Through closer study we may learn how to artificially introduce these systems to climates that are less hospitable.

    --

    You can only be young once, but you can be immature forever.
    1. Re:More than just little green men. by Da+Fokka · · Score: 2, Informative

      The fact that it radiates more heat than it receives implies that there's some kind of heat source within the planet, something like a metal core not unlike earth's.

      When we're capable of artificially introducing something like that into a planet most likely, we're capable of building our own (planets, that is ;).

  19. Reminds me of... by El+Jynx · · Score: 3, Funny

    "Almathea is one of the most unusual moons in the solar system, because it gives off more heat than it ceives from the Sun."

    Funny. My girl does the same thing during the more active cycles.

    --
    A positive attitude may not solve all your problems, but it will annoy enough people to make it well worth the effort.
  20. Just for a minute now... by Qbertino · · Score: 3, Interesting

    ..I just imagined they find an abandoned settlement/station or reactor or something on/in that moon. I mean really. Just imagine.
    That would render all that debating about economy, sadam, snipers and all that stuff irrelevant, wouldn't it?
    Funny to imagine. Things shure would change. For a while that is.

    *sigh* Gotta get that code done... :-)

    --
    We suffer more in our imagination than in reality. - Seneca
  21. Leaves me feeling depressed... by Anonymous Coward · · Score: 5, Interesting
    Every time I read stories on Galileo I get an incredable feeling of depression, not because the mission has been a failure, it has not. Rather that the craft never reached its full potentual. Early in the mission, the main arial to earth never opened meaning that the amount of pictures we get now are much lower then what we should have gotten, Sometimes I think that Galileo could have been the mission which found life on another planet besides earth. This would have changed everything, instead of planning wars today we would be planing probes to discover what the hell was out there.(a real long shot). Things like the pluto express would not have been cancelled, and millions would not be wasted on the ISS - a project which gets all its money just from the cool factor, and like the shuttle a complete waste of resources.

    Probes are the way to go, its just a pity that for every one sent few manage to survive the trip, the payoff is so great.

    1. Re:Leaves me feeling depressed... by raduga · · Score: 4, Insightful
      With the primary arial undeployed the primary effect has been a reduction in the total number of pictures, and the frequency at which they are captured and returned; since the low-gain antenna / tape recorder are still capable of bringing back images of the same quality, just not nearly as many.

      It's disappointing, sure, but even had the arial been fully deployed, we wouldn't have significantly greater resolution, and might not see substantially more detail of Europa's surface. Also, the change in mission priorities might (?) have meant fewer resources spent on magnetometric observations. Events don't seem to change frequently enough on Europa's surface that a few missing frames would have changed our view much.

      (Contrast with Io! What if we'd missed that eruption?)

      --
      First, nothing begins if not opening
    2. Re:Leaves me feeling depressed... by cybrpnk2 · · Score: 3, Informative

      What depresses me is that for the Almathea flyby they've left the camera off to save the expense of the photo team salaries. About the only science that's gonna happen is measuring doppler shift change of the carrier signal from the probe as it gets close to the moon to refine its mass estimate. This is a real shame; Almathea has some kind of interesting chemistry going on that creates unusual bright red and green patches on its surface we have glimpsed only from afar 20 years ago with Voyager...

  22. Jupiter's mass is the cause of the heating by Big+Mark · · Score: 5, Informative

    Jupiter is so heavy that it's inner reigions are incredibly hot - some think it's actually a star that just wasn't big enough to have it's own mass crush it's innards to the point where nuclear fusion occurs and the star is born. It's big enough, though, that the innards are squished to to superheat. It's this heat from the inside that makes Jupiter warm up.

    The moon's heating is accounted for by tidal forces - Jupiter is just so flippin' MASSIVE that it's gravity stretches and squeezes the moon, and these tidal forces make it heat up.

    The surface of Amalthea (sp.?) will be interesting to look at. I think it will have pronounced cracks on the surface where aeons of tidal forces have had their way.

    1. Re:Jupiter's mass is the cause of the heating by Linux_ho · · Score: 2

      And possibly a big ol' breeder reactor might be sitting at the core, if there's enough uranium floating around in there.

      --
      include $sig;
      1;
    2. Re:Jupiter's mass is the cause of the heating by LMCBoy · · Score: 5, Informative

      It's this heat from the inside that makes Jupiter warm up.

      This parses to "Jupiter is hot because it is hot."

      You're correct that Jupiter's core is not hot enough for nuclear reactions (core temperature is about 20,000 K).

      Just to clarify, Jupiter gives off more heat than it receives because it is still collapsing! Sounds incredible, but the "heavier" elements are still slowly settling out toward its core. As they do, they release gravitational potential energy in the form of heat. This settling process must be incredibly slow, since it's presumably been happening steadily for the past 4.6 Gyr; the fact that it still produces a significant amount of heat demonstrates how damn BIG Jupiter is.

      See SEDS.org for more information (about halfway down the page, right after the section on the Great Red Spot).

      --
      Liberal (adj.): Free from bigotry; open to progress; tolerant of others.
    3. Re:Jupiter's mass is the cause of the heating by pogen · · Score: 3, Insightful
      some think it's actually a star that just wasn't big enough to have it's own mass crush it's innards to the point where nuclear fusion occurs and the star is born.

      And that makes it "actually a star" how, exactly?

      You pretty much just gave the definition for why it isn't a star.

    4. Re:Jupiter's mass is the cause of the heating by at_18 · · Score: 3, Informative

      ...some think it's actually a star that just wasn't big enough to have it's own mass crush it's innards to the point where nuclear fusion occurs and the star is born

      For nuclear fusion to start you need about 80 times the mass of Jupiter. (and that would be a really really tiny star. Our one is about 1000 times jupiter, and it's only average).

    5. Re:Jupiter's mass is the cause of the heating by naasking · · Score: 2

      the "heavier" elements are still slowly settling out toward its core.

      I think you mean "in" towards its core. It wouldn't release potential energy if the heavier elements were travelling up.

  23. when does Galileo retire? by peter303 · · Score: 3, Interesting

    Rescued from disaster- NASA figured out how squeeze data throught the 50 times slower backup attenna when the main one failed- the Galileo mission has extended five years beyond its planned lifetime. Exhaustion of nagivation fuel and other priorities for the Deep Space Network will eventually finish this mission.

  24. Requisite Star Wars quote by ThinkingGuy · · Score: 2, Funny

    "That's no moon... It's a space station!"

  25. It's *Amalthea* by notfancy · · Score: 4, Informative

    Sorry to pick nits, but the name is Amalthea (ah-mal-THEH-ah), it means "the Goddess Amal" (IIRC a Babylonian name for Astarte, the Moon goddess). She was the goat that nursed Jupiter (Zeus, actually) in Mount Ida, and whose horn the baby god pulled with his mighty force while playing with her. That horn is called the Cornucopia, or the Horn of Plenty, after Jupiter, ashamed at his own clumsiness, bestowed that gift on the goat as an apology.

  26. Spacecraft dimensions by teridon · · Score: 4, Informative
    From the article:

    Dimensions: The length of the spacecraft is 9 m and, with the high-gain antenna (HGA) deployed, is 4.6 m in diameter.

    Ha! That's great! Except that the high-gain antenna failed to deploy. Fortunately, with some spacecraft reprogramming, Galileo will still acheive about 70% of its original science goals using the low-gain antenna.

    --
    I hold it, that a little rebellion, now and then, is a good thing. -- Thomas Jefferson
    1. Re:Spacecraft dimensions by fluffy666 · · Score: 2, Funny

      And the giant superintellegent Jovian gasbags who get whacked on the head by it will suddenly notice those insignificant 'big asteroids' closer to the sun and declare war on them..

    2. Re:Spacecraft dimensions by Tablizer · · Score: 2

      Except that the high-gain antenna failed to deploy [google.com]. Fortunately, with some spacecraft reprogramming, Galileo will still acheive about 70% of its original science goals using the low-gain antenna.

      That 70% is kind of a fuzzy number. Who knows what they would have discovered if the antennas worked as planned? It is true that most instruments were able to be used at nearly their full potential because they generate low-bandwidth data sets to begin with. However, high-bandwidth consuming studies, such as close-up "movies" of Jupiter's weather patterns may have told us a lot about Jupiter.

      And with less compression needed on photos, we may have had clearer (more enhance-able) pictures of say Europa. But it is true that they got nice data from most instruments regardless of bandwidth problems.

      Antennas and instrument booms have a history of deployment problems on probes. One of the Voyagers had an instrument boom would not lock into place, ruining some gas giant moon cose-ups. A Viking had a seismometer (sp?) that would not work because a springed latch would not jog. Perhaps they should include a long lite robotic arm that can be remotely told what to push on or poke at. IOW, a way to emulate the famous hammer tap to a farky gizmo.

      It seems like moving parts don't like to move in space for some reason. The wide tempurature and pressure variations during the trip perhaps damage lubricants [1]. They can't get rid of all of the moving parts because launch packaging constraints often require "pop-up" equipment.

      [1] Galileo had to sit in storage for a while due to the launch backlog from the Challenger explosion. Some think that the sitting caused the antenna joint libricant to harden.

  27. Mr. Armchair Science butts in. by erik_fredricks · · Score: 5, Informative
    Almathea is one of the most unusual moons in the solar system, because it gives off more heat than it receives from the Sun."

    Actually, Triton (Neptune's largest) does, too, IIRC. All the gas giants do as well.

    In Amalthea's case (as well as Europa and Io), the moon is constantly being contracted and stretched by Jupiter's gravity, and those tidal forces generate heat in the moon's core. You can duplicate this effect by squeezing a piece of styrofoam in your hand and feeling it heat up.

    Of course, all the gas giants have internal heat sources due to the immense gravity in their highly contracted solid cores. Neptune gives off way more heat and light than it receives from the Sun.
    --

    THE GOOD HUMOR MAN CAN ONLY BE PUSHED SO FAR
    Bart Simpson on chalkboard in episode 2F18

  28. New Horizons by Merk00 · · Score: 3, Informative

    The "Pluto Express" you mentioned is named New Horizons. And it's yet to be canceled. In fact, I sat in on a technical discussion of all its subsystems over the summer. It's still on track to launch sometime around 2007. However, Congress has yet to approve funding for New Horizons so its up in the air whether or not it'll actually fly. That said, development for the probe is still on going.

  29. A sneak peak at Almathea by mraymer · · Score: 5, Informative

    Celestia is a 3D space simulator much like OpenUniverse. It's avaible for both Windows and *nix OSes. In it, you can view all the planets, some moons, asteroids, and a fair number of stars. Here's a shot of Almathea. They release add-ons every now and then-- you can even download the recently discovered Quaoar!

    --

    "To confine our attention to terrestrial matters would be to limit the human spirit." -Stephen Hawking

  30. Re:Nice rendered pictures -- Links! by mraymer · · Score: 2, Interesting

    Here's a shot of Almathea and of the Galileo probe itself as seen in Celestia.

    --

    "To confine our attention to terrestrial matters would be to limit the human spirit." -Stephen Hawking

  31. Frozen Ice? by naasking · · Score: 2

    I wonder what sort of strange substance that is...

  32. aerial by Adam+J.+Richter · · Score: 2

    I think aerial is short for aerial antenna, meaning an antenna that is in the air.