More than 61,000 different meteorites have been found on Earth's surface, of which 224 have been identified as martian, including the famous "Black Beauty". Billions of years ago, it was cast off from Mars as a result of an asteroid or comet strike and finally landed on Earth.

The conclusion that these meteorites have actually come from Mars is based on the fact that they have an elemental and isotopic composition similar to the rocks and atmospheric gases studied by spacecraft on Mars.