Unmasking the Face on Mars

What the picture actually shows is the Martian equivalent of a butte or mesa - landforms common around the American West. "It reminds me most of Middle Butte in the Snake River Plain of Idaho," says Garvin. "That's a lava dome that takes the form of an isolated mesa about the same height as the Face on Mars."

"Gee, it doesn't look like a face to me!" by artist Duane Hilton.

Cydonia is littered with mesas like the Face, but the others don't look like human heads and they've attracted little popular attention. Garvin and other members of the MGS Science Team have studied them carefully, however, using a laser altimeter called "MOLA" on board Mars Global Surveyor.

MOLA can measure the heights of things with a vertical precision of 20 to 30 cm (its horizontal resolution is 150m). "We took hundreds of altitude measurements of the mesa-like features around Cydonia," says Garvin, "including the Face. The height of the Face, its volume and aspect ratio - all of its dimensions, in fact - are similar to the other mesas. It's not exotic in any way."

The laser altimetry data are perhaps even more convincing than overhead photos that the Face is natural. 3D elevation maps reveal the formation from any angle, unaltered by lights and shadow. There are no eyes, no nose, and no mouth!

A 3D perspective view of the Face on Mars landform produced by Jim Garvin (NASA) and Jim Frawley (Herring Bay Geophysics) from the latest MOC image (April 8, 2001) and all of the available laser altimeter elevation measurements by MOLA. There is no vertical exaggeration in this ray-traced image. Garvin and Frawley express special thanks to Mike Malin and MOLA science team.

The mesas of Cydonia are of great interest to planetary geologists because they lie in a curious part of Mars, in a transition zone between cratered highlands to the south and smoother lowland plains to the north. Some scientists think the northern plains are all that's left of an ancient Martian ocean. If so, Cydonia might have once been beachfront property.