Mars Global Surveyor burst the bubble of many enthusiasts who thought a Viking orbiter picture showed a face on Mars. It was just a hill (right).
The orbiter succumbed to battery failure after nine years and 52 days in orbit.
The spacecraft operated in orbit at Mars longer than any other spacecraft - four times longer than its planned two-year mission.
It was the first successful mission to the Red Planet in two decades.
Mars Global Surveyor's detailed images of the so-called face on Mars
revealed it to be just another Martian mesa (right), not the evidence of ancient Martians hyped in popular culture.
A malfunction at first seemed to doom Mars Global Surveyor to a shorter mission, but the spacecraft ended up setting an endurance record for work in Mars orbit.
The spacecraft also acted as a communications relay for other Mars missions.