Meteorites from Mercury? |
Meteorites from Mercury? |
Guest_Enceladus75_* |
Oct 28 2008, 07:09 PM
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#1
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Guests |
I see in the current issue of Astronomy magazine (November 2008) that there is a very interesting article about a class of meteorites that are theorised to have possibly originated on Mercury. We now know of meteorites that came from the Moon and Mars, and there might also be some from Venus, but I think that it is fascinating that we may have, right here on Earth, pieces of the innermost planet at hand.
Would it take a sample return mission from Mercury to prove these meteorites came from the planet or could the Messeneger results in the coming years clinch the question? What do others think? |
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Mar 24 2010, 07:08 PM
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#2
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Member Group: Members Posts: 688 Joined: 20-April 05 From: Sweden Member No.: 273 |
The largest (known) young meteor craters are
Kara-Kul, 52 km, c. 5 million years El'gygytgyn, 18 km, 3-4 milllion years Zhamanshin, 14 km, 1 million years Lake Bosumtwi, 10 km, 1 million year It seems that at least Kara-Kul might be large enough for ejecta to reach escape velocity, particularly as it is at 3900 meters altitude, that means a lot less atmospheric drag (though I guess it was probably rather lower back then). Interestingly it is situated inside the Tien-Shan, so any ejected rocks would be fairly young sedimentary stuff (though I suppose the impact would turn them into instant metamorphics). As for really old terran meteorites, I've pointed out before that the best (only?) chance to find out anything about what happened on Earth during the first 500 million years or so is probably to look for terran meteorites on the Moon. It seems that the Late Heavy Bombardment wiped out almost every trace of what happened before c. 3800 million years ago. |
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