The study identified when water interacted with the meteorite and established that the dating was unaffected by events after it left Mars.

An asteroid struck Mars 11 million years ago and sent pieces of the red planet hurtling through space. One of these chunks of Mars eventually crashed into the Earth somewhere near Purdue University and is one of the few meteorites that can be traced directly to Mars.

It was a long journey to this discovery, however, and one that happened partially by chance. About 11 million years ago, an asteroid collided with Mars, sending plumes of debris beyond the planet’s atmosphere. One of those meteorites eventually succumbed ...