A group of unusual meteorites was found in Shergotty, India  Their structure indicates that they originated on one of the geologically active planets, Mercury, Venus, or Mars  Because of Mercury' s proximity to the Sun, any material dislodged from that planet' s surface would have been captured by the Sun, rather than falling to Earth as meteorites  Nor could Venus be the source of the meteorites, because its gravity would have prevented dislodged material from escaping into space
The meteorites, ttherefore, probably fell to Earth after being dislodged from Mars, perhaps as the result of a collision with a large object
offering a counterexample to a theory