Great point that most people don't get. As Robert Zubrin said, you could drop 100 Spirit/Opportunity level rovers into the Rocky Mountains and probably never f

Great point that most people don't get. As Robert Zubrin said, you could drop 100 Spirit/Opportunity level rovers into the Rocky Mountains and probably never find prehistoric fossils, while a team of four human scientists would easily find a lot. The probes are amazing and important, but no substitute for sending humans.