Marsrocks: Thanks for this explanation. I always wondered about this, although it is strange perhaps that no partially uncovered meteorites in the middle of nowhere exists - that we have found anyway. I would expect to see the rock partially submerged in the ground where the 'weathering' has not yet managed to expose it.
Also, there must be more meteorites that have fallen in the millions of years that it has taken to expose these ones. Over millions of years, you would expect more than a few to have fallen and if this was the case, the whole area of this sand-desert-like-area would be littered with meteorites which have been exposed over the millions of years since they fell to Mars.
I dont know, but it does not ring true to me, but then, I am not a planetary scientist.
Sorry, I just have to add this too. The other thing that I find strange is that there is no buildup of soil/dust/sand around the bases of any of these meteorites. Although there is evidence of wind swept soil in the dunes that are nearby, there is nothing in the leeward edge of these meteorites and there is no dip to indicate that the wind has been blowing against it on the windward side. If the rock is standing on other rocks, you would expect those rocks to also have been exposed by the millions of years of wind blowing so that these meteorites would be standing on top of other rock outcrops which also have been exposed by the wind and weather.
-- Edited by qmantoo on Saturday 2nd of October 2010 03:14:38 AM
qmantoo - the official explanation I have read on this (involving one of the previous meteorites) is that this whole area is a "deflation zone."
This means that the land was at one time built up more - higher elevated. Over time, the sand and soil has been blown away from this area to somewhere else- making the land a lower elevated area here. While the sand and soil has been blown away, the larger rocks and meteorites that were once buried under the soil stay behind on the top surface.
The deflation effectively erases any crater or other scars that was once there - as well as removes the soil that may have once buried or partially buried the meteorite.
Possibly this one and Oileán Ruaidh are fractured pieces of the same initial meteorite which broke apart in the Martian atmosphere. The proximity certainly makes it seem plausible.
I wish you would answer the questions relating to this rather than just ignoring them.
In your opinion, how come these meteorites fall from the sky without any marks on the ground, craters, or pieces fallen off them?
Opportunity has spotted another meteorite a short distance from the Oileán Ruaidh meteorite (which has just been confirmed by the alpha particle X-ray spectrometer to be composed of nickle-iron).
Source: 1N338936872EFFARBKP1949L0M1
Possibly this one and Oileán Ruaidh are fractured pieces of the same initial meteorite which broke apart in the Martian atmosphere. The proximity certainly makes it seem plausible.