Rare Meteorites Are From Mars, Curiosity Rover Confirms

Although it's rare, some meteorites that drop in on Earth come from our neighboring Red Planet. We have suspected this for years, but this week, NASA's Curiosity rover confirmed their origin.

Using her Sample Analysis at Mars (SAM) instrument — a highly sophisticated onboard chemistry lab that can conduct hundreds of the same experiments we do on Earth — Curiosity rover found two forms of argon, a noble gas that doesn't react to other compounds. This is an important gas because it tells the straightforward history of Mars, which was once a wet planet similar to Earth