Rover Confirms Meteorite on Mars

Fascinating. I'm all for the theorizing stuff, most of which goes about 17000ft above my head but, when I see something that I can relate to, (I've seen loads of lumps of rock) I begin to feel that I am a part of all this.
I've been following all this Mars stuff since I read a book called 'Mars at Last' which was about the Viking missions to Mars back in 1976. It amazes me that the two Mars rovers, Spirit and opportunity, have exceeded their anticipated missions by several hundred percent.
As a Layman with a capitol 'L' it would seem to me me that good old "Buzz Aldrin" was right when he was asking, during the recent fortieth anniversary of the moon landing celebrations, "What the heck are we doing planning to go back to the moon for when the real next frontier is Mars?" though not in quite so many words. Or as inarticulate.

IF, if it is a meteorite, why is it just sitting on the surface?? Did it land by parachute?

Congrats to all involved in identifying this Martian 'gem'.

It sure looks like a meteorite so there isn't a lot of 'if'. It could have hit a long time ago, most likely did. It could be part of a shattered rock that bounced a bit if it came in at a steep angle.

The key thing I see is there is only a small amount of dust on it. This implies that the dust in that area is being blown out of the area at present. Thus the rock could be several or more feet below its initial impact point and the land around it was later eroded down by wind. This is assuming that the surface there is loose rather than rocky.

I looked at the earlier photo and it does seem to be an area that has been eroded down over time. Quite flat with this rock as the biggest thing in the photo.

Ethelred

This article misses the most interesting bit, which is that the meteor could only have landed intact when Mars had a significantly thicker atmosphere. http://www.sfgate...89OR.DTL&type=science

Curiouser and curiouser.

The meteorite might have landed either in a thick layer of dust or sand (which would have to somehow exist even though wind action must have been greater and Mars a lot wetter back then) cushioning its fall. Or it landed, burying itself deep in some surface more substantial than sand or dust, which then was eroded by wind action sufficient to leave the meteorite sitting proud, but not sufficient to abrade smooth all the contours of the meteorite.

...Or it landed in a body of water?... with no signs of rust?

Sufficient dust need not be abrasive. The air is very thin on Mars so the dust is mostly just . . . dust. Not sand.

with no signs of rust?

No free oxygen so no rust.

Ethelred

Sorry for the new signature. But It Needed Killun.

From QubitTamer's fake profile

Quantum Physicist, torturer of AGW religious zealots like Ethelred because i laugh at his hysterics.

Qubitwit gets the rest of August in my signature for aiming his idiocy at me. Again.

You're missing the point docknowledge makes about when the meteorite would have had to fall if it wasn't to be smashed/melted/deformed. It would have needed a fairly dense atmosphere to brake the meteorite, possibly down to as much as a couple of hundred mph, for it to remain intact. This would have been billions of years ago when I'm guessing that there would have been plenty of wind pushing around plenty of rock debris of all sizes from weathering, vulcanism and meteorite strikes. Presumabably the dust that remains now is a result of the wind action on much of that debris abrading it down to the fine powder it is today.

I had supposed that the appearance of the meteorite was down to being sheltered from the sand blasting it would probably have got - but then your comment about the rust has made me find out something else that is puzzling. There's plenty of iron oxides on Mars (hence the red colour) so I naturally thought that the iron meteorite would also somehow rust. In fact according to this article from Wikipedia

http://en.wikiped...on_metal

"When in contact with water and oxygen, or other strong oxidants and/or acids, iron will rust[...]Other degrading solutions are sulfur dioxide in water and carbon dioxide in water."

There would have been plenty of these solutions in Mar's early history. However the article goes on to describe what kind of rust results -

"Under these corrosive conditions, iron(III) species are formed. Unlike iron(II) oxides, iron(III) oxides are not passivating because these materials do not adhere to the bulk metal. As these iron(III) compounds form and flake off from the surface, fresh iron is exposed, and the corrosion process continues until all of the iron(0) is either consumed or all of the oxygen, water, carbon dioxide, or sulfur dioxide in the system are removed or consumed. [2]"

So it would seem that the rust formed would not have adhered to the iron - and this raises another question. If the meteorite was rusting, with the rust regularly flaking off, then I would have expected all the sharp edges on the meteorite to have been rounded off in time. This doesn't seem to be the case on the right hand side. So again the meteorite seems to have been protected from this treatment, presumably by being buried under sand (or possibly water?).

On the off-chance somebody else is as taken as me by the enigma of this meteorite just sitting there on the surface, there's a really good long thread on UMST where the Mars Rover enthusiasts give it a good going-over with lots of photos and good links. My favourites are the new-to-me cross-eyed photo and the link to a guy who has a theory that the meteorite could have survived a high-speed impact with Mars by flying down! It's cleverly argued, but I can't see much of a resemblance between the Block Island iron meteorite pictured at the top of this article and the space shuttle.

http://www.mail-a...402.html

Also to put the puzzle into specific questions try the segment subtitled 'Five Samples - Many Questions' in

http://www.psrd.h...ars.html