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Space Science

Messenger Discovers "Spider" Crater on Mercury 74

I Don't Believe in Imaginary Property brings us a Washington Post story which discusses how scientists are finding surprises among the pictures sent back from Mercury by the Messenger spacecraft. In particular, images depicting a crater with over 100 troughs radiating out from it are stumping researchers. The crater is referred to as 'The Spider', and it occupies a basin that has turned out to be larger than once thought. NASA also has a discussion of the crater. The Messenger craft began taking the up-close photos earlier this month. From the Post: "Scientists were also surprised by evidence of ancient volcanoes on many parts of the planet's surface and how different it looks compared with the moon, which is about the same size. Unlike the moon, Mercury has huge cliffs, as well as formations snaking hundreds of miles that indicate patterns of fault activity from Mercury's earliest days, more than 4 billion years ago."

Messenger Discovers "Spider" Crater on Mercury

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  • Its a cosmic water balloon strike.
    A comet impacted and splatted its matter all over.
  • Hmm... (Score:2, Funny)

    Is it the Great Stone Ass of Mars? []
  • by ErroneousBee ( 611028 ) <neil:neilhancock[ ].uk ['.co' in gap]> on Friday February 01, 2008 @09:32AM (#22260002) Homepage
    Clearly, those are water channels running into the crater.

    Obviously at some point Mercury was hollow and covered by an ocean, then an asteroid hits, punctures the surface, and the ocean drains into the center of the planet, creating the channels we see today.

    Now, I know there are those who will say "but liquid water cant exist that close to the sun".
    Well, to those people I say "Its not called Mercury for nothing".
    • Big impact, super heated rock.

      Big splash.

      Flow back into depression.

      Make dimple shape you see.

    • I think you're close. The body that crashed into Mercury to create this crater probably generated a lot of heat and energy that spread to the surroundings. This action likely melted something out of the ground (maybe water) and gravity and surface tension did the rest to form these channels down into the crater.

      The reason you don't see such effects on the moon is because of the lower gravity preventing pooling, lack of substances to "melt", less atmosphere to heat up the projectile, etc.

      • by arminw ( 717974 )
        .....The body that crashed into Mercury.......

        What is striking about almost all of the craters is where the material that was gouged out of the surface went. The areas outside of most craters is devoid of material, both from the impacting object, as well as from the planet. It's as if it left the planet entirely. This is true of even the smaller craters presumably made by relatively low energy events that should not have propelled the fragments fast enough for them to escape the planet's gravity.

        Even at the
        • The latest theory of the Siberia 1908 explosion is that the body was so small that it disintegrated/vaporized before it hit the ground. It caused a shock/heat wave that caused severe destruction, but the area directly below the impact site was less damaged than the surrounding areas. I don't have an explanation of where the matter goes, maybe it gets driven into the ground and covered up over time by forces of nature. I'm thinking that there is a lot of heat and energy that plays a factor, but I don't kn
  • It's Just amazing! (Score:3, Insightful)

    by DRAGONWEEZEL ( 125809 ) on Friday February 01, 2008 @09:37AM (#22260034) Homepage
    When I think about how far we have come, I am truly amazed. These pictures are from a flyby too! Imagine what we will get when this thing sits in orbit!
  • by 192939495969798999 ( 58312 ) <info.devinmoore@com> on Friday February 01, 2008 @09:38AM (#22260040) Homepage Journal
    I thought the faults and crustal weirdness on Mercury was from the Sun's insane gravity warping and distorting the planet as it rotates and revolves around the sun (also - the super-hot temperature causes expansion on the hot side, compression on the cool side).
    • by TripMaster Monkey ( 862126 ) on Friday February 01, 2008 @09:46AM (#22260092)
      I wouldn't exactly call it "insane"...the Sun's tidal effects on Mercury are only about 17% greater then the Moon's tidal effects on Earth.
      • Re: (Score:1, Informative)

        by kmac06 ( 608921 )
        Also Mercury is tidally locked with the sun, so even if there are huge forces, they are constant, not varying.
        • by nusuth ( 520833 ) <oooo_0000us AT yahoo DOT com> on Friday February 01, 2008 @10:02AM (#22260208) Homepage
          That is incorrect, Mercury is not tidally locked with Sun. It is in 3:2 spin resonance with Sun, therefore the forces vary slowly (change direction twice for every three orbits) but they are not constant.
        • Tidally Locked? (Score:5, Informative)

          by DeeVeeAnt ( 1002953 ) on Friday February 01, 2008 @10:09AM (#22260282)
          Oh no it isn't!
          "Until radar observations in 1965 proved otherwise, it was thought that Mercury was tidally locked with the Sun. Instead, it turned out that Mercury has a 3:2 spin-orbit resonance, rotating three times for every two revolutions around the Sun; the eccentricity of Mercury's orbit makes this resonance stable. The original reason astronomers thought it was tidally locked was because whenever Mercury was best placed for observation, it was always at the same point in its 3:2 resonance, so showing the same face, which would be also the case if it were totally locked."
        • One year on mercury is 87.97 earth days. One sidereal day is 58.65 earth days. The apparent day if you were on the surface is actually 176 days or 2 mercurial years.

          So the tidal tug for whatever its effect, is varying.

          Don't feel bad. It's only recently that we learned this and in elementary school I learned the whole tidally locked story too.
    • I think the difference is due to their formation. Mercury I believe was formed naturally out of gas and elements like Earth, and so has volcanoes etc. While Moon is probably a breakaway part of earth, which got formed just before solidification of earth started. So that Moon never had a hot core, and so there was no volcanic activity.

      • Re: (Score:2, Informative)

        Actually, you have that backwards. The Moon is covered in volcanic features. The dark "seas" are actually huge lava flood plains formed by volcanoes that were active for about a billion years after the Moon's formation. Mercury lacks these extensive volcanic features, likely because Mercury's crust is under compression making it harder for magma to break through and reach the surface. The compression is likely due to Mercury's massive iron core, which shrunk slightly as it cooled shortly after the plane
    • by H3six ( 1207060 )
      I thought it might be subsidence from ancient lava channels, of course it's very weird looking if it is. It looks like water channels.
    • Hey wasn't this an advertisement for the McDLT, Keep the hot side hot and the cool side cool
  • Why is it so surprising that Mercury is much different volcanically than the moon? Mercury is substantially closer to the sun (duh), and is in a funky spin resonance/tidal lock with it. Temperature also varies by several hundred degrees across its surface. It doesn't seem that shocking to me that it has different seismic and volcanic parameters than the moon.
  • More like sperm.
    • When I saw the image, the first thing I imagined was this: something hits the surface, then lots of wormlike creatures start crawling out of the remnants. Yeah, too many B-movies...
  • by Ranger ( 1783 ) on Friday February 01, 2008 @10:08AM (#22260270) Homepage
    "The spiders are on not on Mars. Get your ass over to Mercury!"
  • Great. (Score:4, Funny)

    by imnojezus ( 783734 ) on Friday February 01, 2008 @10:11AM (#22260310)
    Now I get to have nightmares about "Mercurian Crater Spiders". Thanks Slashdot.
    • While you see those as nightmares, I will be using this for a new D&D adventure!!!!

      P.S. It's just a name, like the Death Zone or the Zone of No Return. All the Zones have names like that in the Galaxy of Terror. -Professor Farnsworth

    • nah, it's just a harmless Google bot crawling there
  • by razorh ( 853659 ) on Friday February 01, 2008 @10:14AM (#22260374)
    Spiderplanet Spiderplanet does whatever a spiderplanet does...
  • by jellomizer ( 103300 ) * on Friday February 01, 2008 @10:17AM (#22260394)
    It is a Shadow Ship. Hiding for thousands of years. Waiting for the year 2268
    • Waiting for the year 2268
      Awesome...we can just leave this for the next generation to deal with...just like Y2K :)
    • Re: (Score:2, Funny)

      by N1ck0 ( 803359 )
      Its clearly the impression of the Flying Spaghetti Monster. See for yourself [] the picture and indentations match perfectly.

      After creating the universe he surely had to stop somewhere for a brief rest. And we all know that since the 1800 there has been an increase in discovering impact craters, colliding galaxies, planets, black holes, cosmic ray bursts, etc. These number of these events are also in inverse correlation to the amount of pirates remaining on earth. Thus this is proof that the 'pirate effec
  • My Forensic Opinion (Score:3, Interesting)

    by flyneye ( 84093 ) on Friday February 01, 2008 @10:19AM (#22260408) Homepage
    Just from what I can see,it looks as though perhaps Mercury isn't as solid underneath its crust as perhaps thought.It looks to me like it was hit causing compression,sunk,then pressure pushed back up causing the cracks which may or may not have guided lava.Mercury,a bad place to visit and I wouldn't wanna live there.

  • Don't try to escape by flying down the central hole, landing, and then getting out and walking about.

    Trust me, it just isn't a good idea.

  • Am I the only one who got excited when I read "Messenger Discovers "Spider" Critter on Mercury"?

    I, for one, welcome our Mercurian Spider Critter Overloads!
  • That's no spider ... it's Cthulhu. I lose 2D4 SAN.
  • was anal fissure.

    I'm blaming all the goatse trolls.
  • Pictures sent in Messenger appear sometimes like craters in my kopete, too. Very disturbing.
  • Its just that a several of MESSENGER scientists lack the imagination and experience of a geologist. Keep your mind open for possible volcanics in the past.
  • It's not even funny how far I am from being qualified to make this guess, but I'll do it anyway....

    Maybe a large asteroid of ice or large comet hit it on the night side and then melted when Mercury turned the crater to the day side, causing all the runoff to create the crazy channels radiating out from the crater?

    Okay, commence ripping this theory to shreds. Ready? Go!
  • Looks like the work of Harmoniums feeding off the vibrations of the impact that created the crater. I guess there were no Chronosynclastically Infundibulated humans around to rearrange the harmoniums to spell 'This is no moon'. /Vonnegut Tribute
  • The shadow vessel got lost and will be heading to Mars soon, nothing to see here, move along.
  • If you review radar imagery of the Calderas of Venus, you find similar features to the "Spider" crater of Mercury. IMHO, the Spider is a collapsed Volcano. The interior expands with molten material which then vacates and permits a collapse of the volcanic structure, causing the radial channels. The largest channel appears to be due to a lava flow. Also uncharacteristic of an impact crater is the steepness of the walls and the height of the central peak, i.e. disproportionate to the size of the crater.
  • Hahaha, who tagged this 'sendinronwealsey'?
  • As you know, Mercury is an anomalously heavy planet for such a small object. One widely accepted theory is that sometime in the distant past, Mercury was much bigger and suffered from a collision that ripped away most of Mercury (the abundance of craters means that it must have happened a very long time ago). Recently, we have discovered planetary systems orbiting around other stars. One thing that a lot of these systems feature is a large Jupiter-like gas planet orbiting close to the star. In fact, our so
  • Mercury looks more and more like crematoria [from ridick] if it had that same kind of reactive surface as crematoria. It once may have had that kind of effect and has simply just exhausted its surface of reactive material. This would explain some of the surface scaring and channels.
  • by L. J. Beauregard ( 111334 ) on Friday February 01, 2008 @07:37PM (#22268508)

    FAIL. Mercury has about 1.4 times the Moon's radius and 4.5 times its mass.
  • Since spiders have only eight legs, wouldn't "Spider Web" be more appropos?

    Further, the appearance suggests the fracturing of a hard surface. Is the surface glassine in nature?

  • i keep thinking about Vernor Vinge's Book [] because of this thread.
  • Looks more like "the pre-streching goatse crater"...

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