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Space News

Saturn's Moon Enceladus Has an Atmosphere 224

Posted by samzenpus from the quite-but-a-little-chilly dept.
Dimentox writes "The Mercury News reports that the international Cassini spacecraft has discovered that Saturn's moon Enceladus has a significant atmosphere, NASA said Wednesday. The icy moon's atmosphere may be created by volcanism, geysers or gases escaping from the surface or the interior, the space agency's Jet Propulsion Laboratory said. Excluding Saturn's giant moon Titan, which was already known to have an atmosphere, it's the first discovery of an atmosphere on one of the more than 30 moons that orbit the ringed planet."
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Saturn's Moon Enceladus Has an Atmosphere More

Saturn's Moon Enceladus Has an Atmosphere

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  • Enceladus has atmosphere... (Score:5, Funny)

    by Anonymous Coward on Wednesday March 16, 2005 @08:09PM (#11960569)
    but, alas, lacks ambiance. We give it one star.

  • Second First (Score:5, Funny)

    by LakeSolon ( 699033 ) on Wednesday March 16, 2005 @08:09PM (#11960572) Homepage
    Excluding Saturn's giant moon Titan, which was already known to have an atmosphere, it's the first discovery of an atmosphere...

    Excluding the first it's the first? We have a word for that. "Second".

    ~Lake

    • Re:Second First (Score:4, Insightful)

      by aussie_a ( 778472 ) on Wednesday March 16, 2005 @08:18PM (#11960663) Journal
      Excluding the first it's the first? We have a word for that. "Second".

      People tend to think that the second isn't important, so they like to make stuff the first. It is the first that this probe has discovered. Titan having an atmosphere has been known for some time, this is the first discovery of one of Saturn's moons having an atmosphere in quite a while. This is also what the article meant.

      So while your comment has been marked interesting, it's really not. It's pedantic more then anything.

      • Re:Second First (Score:3, Insightful)

        by Anonymous Coward
        It's a lame excuse to make it sound like it's more important than it is. It's like "Columbus was the first to discover the Americas, excluding the vikings and the people already living there."

        It's an attempt to give credit where it isn't due and to inflate the importance of an event.
    • It's the first discovery of a moon around Saturn that has an atmosphere by the Cassini probe. There's 30+ moons around Saturn and the probe has just begun its mission. It's quite possible that it will find more and more moons with atmospheres.
      • ... and people thought that Firefly [serenitymovie.com]'s copious use of the word 'moon' was just a writer's fancy ... :)

        disclaimer: that link gets me five credits for each click ... click away! And don't forget to watch the movie in September! :)
      • This is the first time since Cassini arrived in orbit around Saturn last summer that an atmosphere has been detected around a moon of Saturn, other than its largest moon, Titan.

        That's the actual quote from the article, which says what you said. But that's different from what the summary said. Which is what I was commenting on.

        And for the record I wasn't trying to be insightful, or interesting, just make a wise crack about the poorly written summary. I suspect the non-funny mods were simply an attempt to
    • I can't wait for the next first time we find a moon with an atmosphere!

      -
  • The icy moon's atmosphere may be created by volcanism, geysers or gases escaping from the surface or the interior, the space agency's Jet Propulsion Laboratory said.

    Gases escaping?

    It's the GNOMES!

  • Nice discovery for the bad news (Score:4, Insightful)

    by nsasch ( 827844 ) on Wednesday March 16, 2005 @08:11PM (#11960600)
    It's really great news for the mission especially after the wind measurement tool didn't function properly at first. 15 more years, and there'll be a space craft at this moon.

  • It would be nice to link to the actual article (Score:5, Informative)

    by PxM ( 855264 ) on Wednesday March 16, 2005 @08:12PM (#11960614)
    Link [mercurynews.com] It should be noted that this isn't an atmosphere in the common sense. The air is continually created and lost due to internal sources and weak gravity.

    --
    Want a free iPod? [freeipods.com]
    Or try a free Nintendo DS, GC, PS2, Xbox. [freegamingsystems.com] (you only need 4 referrals)
    Wired article as proof [wired.com]

  • Excluding.... (Score:5, Funny)

    by jbum ( 121617 ) on Wednesday March 16, 2005 @08:13PM (#11960622)
    Excluding the more than 30 moons that orbit the ringed planet, it's the first discovery of a moon orbiting the ringed planet!

    • Excluding thirty moons, a few billion tonnes of rock and ice debris in the form of a giant set of inexplicable rings, and a giant gas planet that is now considered likely to have a solid core, the press have finally discovered something interesting to talk about. Cassini!

  • significant? (Score:3, Interesting)

    by Anonymous Coward on Wednesday March 16, 2005 @08:15PM (#11960634)
    *Any* atmosphere on a sub-500km wide moon [nineplanets.org] would be significant. I'm looking forward to a more complete report as more information comes in.

    Why am I suddenly hungry for Mexican food?

  • I wonder what else we're missing? (Score:4, Insightful)

    by cubicle_cowboy ( 521716 ) on Wednesday March 16, 2005 @08:17PM (#11960649)
    I know this argument is getting old, but this is a good example why we should be spending more money on unmanned probes instead of high-cost, low-science manned missions like the space station. There's little reason at the moment to spend large sums of taxpayer cash on things that provide little benefit. Imagine all the probes we could be sending instead. A whole fleet of Cassinis, Voyagers, and Mars Rovers combing the solar system! Let the private industry (ie. the guys with Scaled Composites and maybe even Virgin ;) take the baton on manned space flight. Hopefully the private industry will find ways to lower the costs so that when we finally need people in space, it'll be practical.

    • Re:I wonder what else we're missing? (Score:5, Insightful)

      by QuantumG ( 50515 ) <qg@biodome.org> on Wednesday March 16, 2005 @08:25PM (#11960726) Homepage Journal
      and all the research that needs to be done to make living in space actually possible is going to happen where? Frankly, if we're ever going to go to Mars, we need to learn how to live in space for extended periods of time. Even with our best propulsion systems it will take at least 18 months to get to Mars. During that time astronauts need to live in the ship. That makes your space ship a space station. So how in the world are we supposed to build a self sustaining space station that we can fly to another planet if we can't even sustain one in low earth orbit?

      Excluding the creation of some buck rodgers form of space propulsion the ISS is the best bet we've got for space colonisation.

      • Comment removed based on user account deletion
      • and all the research that needs to be done to make living in space actually possible is going to happen where?

        Bigelow Aerospace [popsci.com] seems to be making a good bit of progress in that arena. Granted, a lot of their technology came from the NASA-funded Transhab project.
      • What they are really advoacting is that we NEVER send humans into space again. After all, why send anyone away from the earth when we can just always send a video camera on treads? Why not just keep developing better video cameras instead of going to all the trouble to actually set researches on-site?

        Or so the thinking goes. I fail to understand it either, as the thinking is as inherantly alien to me as martian microbes.

        There are many that would advocate complete abandonment of any manned space efforts

  • How unique is this? (Score:4, Interesting)

    by jerkychew ( 80913 ) on Wednesday March 16, 2005 @08:19PM (#11960669) Homepage
    Please bear with me, as I never paid any attention to astronomy-related stuff. I'm just curious as to how many other planets/ moons/ celestial bodies out there are known to have an atmosphere? Is this a really big deal, or is it a relatively common occurance?

    • Re:How unique is this? (Score:2, Informative)

      by Anonymous Coward
      Well, it'd be the 2nd moon ever with an atmosphere, and the 7th body in total with one (although Pluto probably has one, but that hasn't been proven).
      • Triton also has an atmosphere... very thin... but probably as
        dense as Enceladus and denser than Pluto.

      • Re:How unique is this? (Score:3, Informative)

        by l810c ( 551591 ) *
        Could you name the ones you know of?

        I've done some googling and have come across conflicting answers. One site lists only Titan as having an Dense atmosphere. Another lists Io, Europa and Triton with Tenuous(require regeneration) atmospheres as well. This new moon would seem to fall in that category.

        And the planets?
        Venus, Earth, Mars and maybe Pluto?

        • Pluto has an atmosphere; the atmosphere actually freezes when Pluto is distant from the sun and thaws when it gets closer again.

        • Re:How unique is this? (Score:5, Interesting)

          by jd ( 1658 ) <imipakNO@SPAMyahoo.com> on Thursday March 17, 2005 @01:52AM (#11962753) Homepage Journal
          The Gas planets have atmospheres. Well, if they didn't, they'd be a lot smaller.


          Europa has H2O in both ice and liquid forms, which is horribly unlikely at near-zero pressure, which means it almost definitely has an atmosphere.


          Any comet can be considered as having an atmosphere, whilst it is close to the sun and being frazzled. However, I think there are some who consider that cheating.


          Any object close to (or larger than) the size of Mars is going to have an atmosphere, provided at least one of the following conditions is met:


          • After the planet formed there was a liquid core capable of generating and sustaining geological activity such as volcanos, geothermal vents, etc.
          • Gasses or liquids start on the surface where the rate of loss into space is equal to or exceeded by the rate of replenishment. (Replenishment may include geological activity, meteorites containing suitable compounds, etc.)
          • After the planet formed, it encountered an atmosphere (most likely from a comet that didn't quite hit) that it could then capture and retain.
          • After the planet formed, it encountered the necessary compounds by actual impacts from cometary fragments, meteorites, etc.


          The gas giants can form either from a cloud that coalesces as per a rock planet, but never actually becomes solid, OR when a very large rock planet sweeps enough lighter material to build an atmosphere around it. Jupiter is now thought to be of the first kind, Saturn of the latter.


          There may be other ways an atmosphere can form, but these would seem to be a good start on a list.

          How can an atmosphere NOT form on a planet?

          • It started off with one, but
            • It escaped faster than it could be replenished (planetary spin too high, insufficient gravity and/or too high a temperature)
            • The source material or driving force used to replenish it ran out
            • It froze solid
            • It chemically reacted with something to become part of the surface
          • It didn't start with one and
            • There are no processes to generate one internally
            • There is nothing on the surface suitable and at the right temperature
            • It has never encountered suitable frozen material in cometary fragments that could supply one
            • It has never encountered free-floating gas molecules in sufficient quantity AND that is sufficiently massive to be captured and stay on the planet AND isn't moving fast enough relative to the planet to escape.

          I don't know what the odds are for any of these, but it would seem reasonable to suppose that 20-30% of all moons will have some sort of atmosphere, and maybe 60-80% of all planets do. We've not found many small extrasolar planets, so we can't tell from that. However, if you go by mechanisms, those percentages feel reasonable enough.

          • It escaped faster than it could be replenished (planetary spin too high, insufficient gravity and/or too high a temperature)

            AFAIK, planetary spin cannot cause a planet to lose it's atmosphere.

      • All the planets have an atmosphere of some sort. Mercury is trace, but there is something, a little something.

        Venus to Pluto have atmo, so there are 8 bodies and Io, Callisto, Ganymede, Titan, Enceladus and Triton.
        • Is more like a few of those super-ball thingies bouncing around a really roomy tank. The particles don't even interract with each other: the most prevalent collision is by far the particles with the surface. In fact, there's some question about solar pressure 'blowing' away the atmosphere. (though it would be replenished by solar wind particles) On earth would be very difficult to get a vacuum of the quality of mercury's "atmosphere." calling it a trace is extremely generous.
      • "Well, it'd be the 2nd moon ever with an atmosphere"

        Except for earth's moon, you mean, right? Come on, moderators, don't take random, ill-informed comments at face value.

  • All your base are belong to us? (Score:5, Funny)

    by Jugalator ( 259273 ) on Wednesday March 16, 2005 @08:27PM (#11960746) Journal
    The Mercury News reports that the international Cassini spacecraft has discovered that Saturn's moon Enceladus has a significant atmosphere, NASA said Wednesday.

    Not only that, but I bet there's an entire rebel base there [nasa.gov] as well!
    NASA should better send down a probe there to check it out.

  • First? (Score:4, Insightful)

    by IWannaBeAnAC ( 653701 ) on Wednesday March 16, 2005 @08:31PM (#11960791)
    Excluding Saturn's giant moon Titan, which was already known to have an atmosphere, it's the first discovery of an atmosphere on one of the more than 30 moons that orbit the ringed planet.

    So, you really mean that it is the second moon of Saturn found to contain an atmosphere? Why not say just that?

    • Because Titan is in a class by itself in the Saturnian system. Titan is the only large moon there, so the rules are expected to be generally rather different.

  • international? (Score:3, Insightful)

    by minus_273 ( 174041 ) <aaaaa@NOspam.SPAM.yahoo.com> on Wednesday March 16, 2005 @08:36PM (#11960845) Journal
    i know bashing the US is cool, but isn't this a NASA project paid for by the US tax payers?

  • MMMM. Mexican Food! (Score:3, Funny)

    by levitater ( 841381 ) on Wednesday March 16, 2005 @08:50PM (#11960963)
    Homer: Mmmmmm.... Moon Enchiladas.

    Comic Book Guy: For your information, my corpulent comrade, it's "Enceladus," who in Greek mythology was a giant who was defeated in battle and buried under Mount Etna by Athena.

  • So. . . does that mean *I* have an atmosphere? (Score:4, Funny)

    by jafac ( 1449 ) on Wednesday March 16, 2005 @09:01PM (#11961050) Homepage
    ...The icy moon's atmosphere may be created by ...gases escaping from ... the interior...

    That could describe a lot of people I know.
  • Well, you know, half the developers in Atlanta are trying to figure out how to put their next development in place.

    And then justify the commute.

  • First Post! (Score:5, Funny)

    by psychgeek ( 838231 ) on Wednesday March 16, 2005 @09:44PM (#11961356)
    Excluding the posts above, I *finally* have a first post.....

  • The Mercury News? (Score:2, Funny)

    by Anonymous Coward
    Shouldn't the Saturn News be reporting this?
  • ... have they found where the black obelisk is located?

  • International Cassini spacecraft? (Score:3, Informative)

    by i41Overlord ( 829913 ) on Wednesday March 16, 2005 @11:48PM (#11962149)
    Cassini is NASA. ESA was the Huygens probe.

    If both NASA and the ESA want to share credit for the whole mission, fine, I'd go with that. But that didn't seem to be the attitude when the Huygens probe landed on Titan. When that happened, I recall the ESA being *very* specific that it was their probe- and their accomplishment, and not NASA's. I thought that was a bit rude. In other words they want to share partial credit for what isn't thiers, but they want to take total credit for what is theirs.
    • The Cassini orbiter is almost only NASA but not entirely. I do think that if we're going to cooperate with NASA we should be more objective about who contributed with what. Luckily, media over here was pretty good in pointing out how Cassini was mainly a NASA project while Huygens was mainly a ESA project.
    • We were promised spectacular pictures but all we got was some grainy poor quality B&W pics and one false colour one of the surface. Given this is probably the first & last landing on titan for decades I think they could have put in a better camera. Even viking managed better quality pictures back in 1976.
  • Now we don't have to send that probe [slashdot.org] to Europa. We all know how bad [irtc.org] that would be.
  • FreeAtmospheres.com [FreeAtmospheresOnTheMoonsOfYourChoice.com]
  • Maybe it's a good thing I'm *not* employed as a scientist.
    This way I can butcher the pictures.

    Here is the link to the Enceladus image I cooked up to bring out all those surface features instead of that drab grey.
    Enceladus Feature Contrast [spacescience.ca]
  • Do they mean that if you stood on the surface you could feel a breeze, could you fly in it? Or do they simply mean that it has a measurable presense via a number of instruments? It doesn't even appear on the photos so it can't be that substantial.
  • that scientists think alien life would need water, oxygen and heat to survive. there is life at the bottom of the ocean that survives on sulphur and the heat from vents - there's almost no oxygen down there. Who's to say life on another planet wont be more obscure?

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