Astronomy/Meteorites from Mars
How can it be that meteorites from Mars can be found on Earth like the metorite that was found in Antartica. If it is from Mars how would it achieve the escape velocity from Mars to reach us?
Simple, something threw it into space. During the early solar system, Earth experienced something called "The Great Bombardment" (which as it's name suggests was a time when Earth experienced an impact about once every two - three hours). By comparsion, nowadays we are impacted about once every ten - twenty years. And just like Earth, Mars gets impacted as well. If something impacts Mars hard enough, then Martian rocks get flung up into the air and here's where the difference occurs. For something to leave the gravity of Mars it only needs to be travelling at 11,184mph (by comparsion the lowest average impact speed of Earth impactor is a mere 22,368mph) so therefore it doesn't take much of an oomph to get something from Mars into space and therefore arrive on Earth