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Mercury - a left-over of the crash that created the Moon?, Highly speculative but maybe worth it
karolp
post Dec 7 2007, 12:19 PM
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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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ElkGroveDan
post Dec 7 2007, 04:04 PM
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The lunar formation theory is predicated on very specific orbits and masses for the bodies both prior-to and after the encounter. So there wouldn't be any missing material to create another planet. Now you could argue that there was a larger initial mass in the system, but then you have to take into account different orbits, velocities and angular momentum of the bodies which would affect a whole host of other things going all the way back to the stability of the system during the formation of the Earth and it's impactor twin in the first place.

Also keep in mind that this event was an unlikely planetary cue ball in the corner pocket. To account for Mercury from this event you'd need a secondary lucky shot to put it in a place where it wouldn't be swallowed by the Sun our fly off to the far corners of the solar system. If you've ever played with a speeded-up planetary system simulation program, its really quite difficult to place a body in a longterm stable orbit. It's an interesting thought, but I don't think it works here.


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karolp
post Dec 7 2007, 04:49 PM
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Thank you for your swift answers. However, I did not mean forming Mercury from leftovers but simply SURVIVING, with its outer layers stripped off in the grazing impact with the Earth. I also thought that after passing the Earth it might have undergone some kind of gradual orbital decay caused by some finer debris near the Earth-Moon system, which started spiralling towards the Sun and dragged on Mercury. It is now in a stable but ELLIPTICAL orbit. Also, it bears a strong resemblance to the Moon in many respects. I realise this is just speculation based on certain facts with a tiny little bit of intuition, but maybe it is a good warmup for focusing on investigating Mercury next year.


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Posts in this topic
- karolp   Mercury - a left-over of the crash that created the Moon?   Dec 7 2007, 12:19 PM
- - ngunn   The computer simulation (or was it just an illustr...   Dec 7 2007, 01:00 PM
- - ElkGroveDan   The lunar formation theory is predicated on very s...   Dec 7 2007, 04:04 PM
|- - karolp   Thank you for your swift answers. However, I did n...   Dec 7 2007, 04:49 PM
- - Phil Stooke   Quite right, EGD. The hardest part is getting the...   Dec 7 2007, 04:52 PM
|- - JRehling   QUOTE (Phil Stooke @ Dec 7 2007, 08:52 AM...   Dec 8 2007, 01:26 AM
- - ngunn   With the greatest of respect to our two sceptics, ...   Dec 7 2007, 09:24 PM
|- - ElkGroveDan   QUOTE (ngunn @ Dec 7 2007, 01:24 PM) but ...   Dec 7 2007, 10:17 PM
|- - karolp   How about seeing this on SPACE.COM in a year's...   Dec 7 2007, 10:36 PM
- - MarsIsImportant   Could Mercury have been created from a planetary c...   Dec 8 2007, 06:46 AM
- - edstrick   A mega impact cause for Mercury's high density...   Dec 8 2007, 11:39 AM
- - ngunn   QUOTE (ElkGroveDan @ Dec 7 2007, 10:17 PM...   Dec 8 2007, 05:52 PM
|- - Rob Pinnegar   QUOTE (ngunn @ Dec 8 2007, 10:52 AM) Actu...   Dec 8 2007, 07:53 PM
- - nprev   Beginning to wonder here if the detailed history o...   Dec 8 2007, 09:20 PM
|- - JRehling   QUOTE (nprev @ Dec 8 2007, 01:20 PM) My o...   Dec 8 2007, 09:58 PM
- - nprev   Hmm. Thanks, JR. Well, how's this, then: Merc...   Dec 8 2007, 11:33 PM
|- - JRehling   QUOTE (nprev @ Dec 8 2007, 03:33 PM) Hmm....   Dec 9 2007, 04:58 AM
- - vk3ukf   Hi, I never realised that Mercury has such a stran...   Dec 28 2007, 08:15 PM
|- - JRehling   Yes, Mercury has a pretty notably eccentric orbit....   Dec 28 2007, 08:22 PM
- - qraal   Mercury is like a Mars minus a big chunk of mantle...   Oct 26 2008, 05:40 AM


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