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Martian Meteorite Gets NASA Mars Rover's Attention
coondoggie writes "NASA's Mars rover Opportunity will take a small detour on its current journey to check out what could be a toaster-sized iron-based meteorite that crashed into the Red Planet. NASA scientists called the rock 'Oileán Ruaidh,' which is the Gaelic name for an island off the coast of northwestern Ireland. The rock is about 45 centimeters (18 inches) wide from the angle at which it was first seen on September 16."
Mars->Earth is comparatively easy because Mars has much lower gravity and (nowadays) has quite a thin atmosphere. I'm not sure Earth->Mars is even physically possible. It would certainly be many, many times less likely.
In any case, out of the many thousands of meteorites found on Earth, less than a dozen are known from Mars. So it's very unlikely that the few examples that Opportunity has found are anything other than the usual bits and pieces from collisions in the asteroid belt. The iron-nickel nature of the ones found so far is consistent with such an interpretation. Iron-nickel ones are from broken-up asteroids where the process of chemical and density differentiation caused the iron-nickel to sink towards the core of the asteroid, and then it was smashed by collision -- you can't get iron-nickel meteorites by blasting at the surface of Mars or Earth because iron-nickel isn't exposed on the surface, it's deep in the core of the planets.