Currently there are six Earth satellites in orbit around Mars, and three Earth robots on the surface. The latest robot to land, the Phoenix Lander, touched down on Sunday afternoon. But as Oobject reminds us, there are at least 12 missions to Mars that have been lost. Pictured is Mars 1, a satellite sent to Mars in 1962 by the Soviet Union, whose communications were lost while it was en route to the red planet. Another famous lost mission was the Polar Lander, which vanished mysteriously near the Martian south pole several years ago (pictured below).
The Polar Lander, launched in 1999, was zooming along just fine until communication was lost on entry into the atmosphere. Most speculate that it simply malfunctioned and crashed, though none of the satellites currently in orbit have imaged the remains. Perhaps for this reason, there has been a lot of lively speculation that it may have been destroyed by an alien outpost. So far, no aliens have harmed any of the other robots on Mars — including the Phoenix Lander, which is also in a polar region (the north pole).
Check out ten more ill-fated robots and satellites who never made it to their Martian destination.
12 Mars Mission Failures [Oobject]