NASA’s Perseverance Mars rover landing: Why do we keep going back to the Red Planet?

With hundreds of worlds in the solar system to explore, it’s fair to ask as NASA’s Perseverance rover makes its final approach for landing Thursday (Feb. 18): Why do we keep going back to Mars?

After all, many dozens of spacecraft have visited the Red Planet since the 1960s, and a good portion made it down safely to the surface, too. We’ve found evidence of water, organics, methane and more — what else is there to explore, one might ask?