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."
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".
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.
.....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.
(just to be an anal retentive geek, photons often overlap/"touch" since they are bosons. Remember, these are wave/particles aka. "wavefucntions" so photons Definitely touch, electrons less so but they "touch" too. there's definitely piles of 'empty space' between the electrons and the nucleus, though.)
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!
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).
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.
Oh no it isn't! http://en.wikipedia.org/wiki/Tidal_locking#Planets [wikipedia.org]
"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.
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
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.
Its clearly the impression of the Flying Spaghetti Monster. See for yourself [venganza.org] 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
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.
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!
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
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.
FAIL. Mercury has about 1.4 times the Moon's radius and 4.5 times its mass.
It doesn't really matter to me, because his and Roland's stories are much more likely to be of interest to me than stories from just about any other major submitter (with the possible exception of NewYorkCountryLawyer).
Let's celebrate when someone can consistently send us interesting stuff.
Cosmic Water balloon (Score:2, Funny)
A comet impacted and splatted its matter all over.
Hmm... (Score:2, Funny)
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Oops. (Score:1)
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Evidence of Water! (Score:4, Funny)
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".
Evidence of Lava! (Score:1)
Big splash.
Flow back into depression.
Make dimple shape you see.
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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.
--Dan
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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
Photons (Score:1)
Space bugs... (Score:2)
It's Just amazing! (Score:3, Insightful)
Faults from extreme tides, etc (Score:5, Insightful)
Re:Faults from extreme tides, etc (Score:5, Informative)
Parent
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Re:Faults from extreme tides, etc (Score:5, Informative)
Parent
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Tidally Locked? (Score:5, Informative)
http://en.wikipedia.org/wiki/Tidal_locking#Planets [wikipedia.org]
"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."
Parent
Not tidally locked. (Score:2)
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.
Probably Moon was formed later (Score:3, Interesting)
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How surprising really? (Score:1)
Looks less like spider (Score:2, Insightful)
Ground Control to Major Tom (Score:5, Funny)
Great. (Score:4, Funny)
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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
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spider planet (Score:5, Funny)
The Shadows are comming. (Score:3, Funny)
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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)
Obligitory, but slightly modded quote (Score:1)
Whatever you do... (Score:2)
Trust me, it just isn't a good idea.
Spider Critters? (Score:2)
I, for one, welcome our Mercurian Spider Critter Overloads!
That's no spider (Score:2)
My first thought (Score:2)
I'm blaming all the goatse trolls.
Puzzles me too (Score:1)
any geologist woudl call it a volcanic crater (Score:2)
Maybe a large "icesteroid" or comet? (Score:2)
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!
sendinronweasley (Score:2)
Meteorite impact and theory about heavy core. (Score:2)
Reporter not paying attention (Score:3, Informative)
Only eight legs? (Score:2)
Further, the appearance suggests the fracturing of a hard surface. Is the surface glassine in nature?
"Spider"? (Score:2)
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Let's celebrate when someone can consistently send us interesting stuff.
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