Professor: Why Earthlings Are So Obsessed With Mars

It's been centuries since Earthlings last gave Mars a moment's peace. From the first time we noticed it hanging in the sky — closer than other worlds, brighter than other worlds, unsettlingly redder than other worlds — we have alternately loved it, feared it and hung our hopes for life in the lonely cosmos on it. That romance is as passionate as ever. There are currently eight active spacecraft orbiting or on the surface of Mars — two of them rovers.