Big Mars Impact Gave Earth Most of Its Martian Meteorites

A huge meteorite impact on Mars five million years ago blasted toward Earth many of the rocks that scientists scrutinize to learn more about the Red Planet, a new study reveals.
The cosmic crash left a 34-mile-wide (55 kilometers) gouge on Mars called Mojave Crater and is the source of all “shergottite” or igneous rock Martian meteorites found on Earth, researchers say. Examining the crater and the meteorites also led to new revelations about how old the rocks are.