NASA's rover Curiosity made two significant discoveries recently in the Gale crater on Mars.
According to NASA, the rover found evidence of organic matter inside a mud-rock dating back 3.5 billion years.
The Curiosity rover touched down inside the crater years ago because NASA thought it was an ancient lake bed, where life may have formed.
Although Curiosity hasn't found evidence of life yet, the rover has found evidence that Mars was once a habitable environment.
