Mercury - a left-over of the crash that created the Moon?, Highly speculative but maybe worth it |
Mercury - a left-over of the crash that created the Moon?, Highly speculative but maybe worth it |
Dec 7 2007, 12:19 PM
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Member Group: Members Posts: 147 Joined: 14-April 06 From: Berlin Member No.: 744 |
Having agreed upon the Moon being created by a grazing collision with a Mars-sized object, could we give any thoughts to what happened to the impactor afterwards? Since it was a grazing collision, it might have been melted but not destroyed, only with some material ripped from it (and from the Earth) which ended up in Earth orbit to coalsce into what we know as the Moon today. But what happened to the impactor after it passed the Earth? Could it still hang around somewhere in the Solar System? I suppose it would bear some significant markings after the event, for instance have its outer layers stripped. But wait a second... Mercury DOES have its outer layers stripped off, with an unusually high mean density resulting from a core which could be considered oversized for such a small planetary body. In the wake of MESSENGER beginning to reveal Mercury's secrets in January, could anyone bother to give any thoughts to this idea? I am not sure whether it had been put forth previously or not, I am just curious if it could make any sense to have the impactor impact the Earth in a grazing manner and then end up parked in an elliptical orbit close to the Sun, with its outer layers stripped and an "oversized" original core left inside...
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Dec 8 2007, 11:33 PM
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Merciless Robot Group: Admin Posts: 8783 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
Hmm. Thanks, JR.
Well, how's this, then: Mercury formed where it is, has always been there. During the Sun's T Tauri phase & subsequent period of greater luminosity (as much as 30% higher than that of today), Mercury lost all of its volatiles, including a significant fraction of slightly heavier elements that the outer planets retained. After differentiation & the LHB, what's left is basically a ball of molten iron with a relatively thin shell of silicates. Problem: Earth's average density is actually higher than that of Mercury, in fact the highest of all the Sun's planets. If the preceding scenario was correct, you'd think that Mercury would be denser... -------------------- A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
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