Scientists are confirming that 15 pounds of rock collected recently in Morocco fell to Earth from Mars during a meteorite shower last July.
This is only the fifth time in history scientists have chemically confirmed Martian meteorites that people witnessed falling. The fireball was spotted in the sky six months ago, but the rocks weren't discovered on the ground in North Africa until the end of December. [...]
Astronomers think millions of years ago something big smashed into Mars and sent rocks hurtling through the solar system. After a long journey through space, one of those rocks plunged through Earth's atmosphere, breaking into smaller pieces.
Most other Martian meteorite samples sat around on Earth for millions of years — or at the very least, decades — before they were discovered, which makes them tainted with Earth materials and life. These new rocks, while still probably contaminated because they have been on Earth for months, are purer.
The last time a Martian meteorite fell and was found fresh was in 1962. All the known Martian rocks on Earth add up to less than 240 pounds.
http://www.google.com/hostednews/ap/article/ALeqM5glF4ifo7dJD3j5qIbC6WqqWNZI0w?docId=ee4fe5108eac44b8b28609cfa241aacc -via io9 | Photo: Darryl Pitt