Millions of miles from Earth lies a dusty, cold, desert world with a very thin atmosphere. You know this planet as Mars…but it hasn’t always been this way. There’s evidence that the Red Planet was much wetter and warmer, with a thicker atmosphere, billions of years ago. Could it also have supported life? NASA’s Perseverance rover launches next week and will explore the Red Planet to collect rock and soil samples, which may preserve ancient signs of life.