October 1997: An American spacecraft lost on Mars for 21 years has finally been located by a geography professor at The University of Western Ontario. Using a technique of his devising, planetary expert Phil Stooke has pinpointed the exact location of the Viking 2 spacecraft which landed on Mars on Sept. 3, 1976. The discovery could lead to a more precise mapping of the planet.
"People had basically given up because the task seemed too hard in the past," says Stooke, "but by bringing some new ideas to it, I was able to solve the mystery."
The Viking 2 spacecraft landed on Mars about two months after its twin probe, the Viking 1. Viking 1 was easily located because it touched down in an area with visible hills and craters. By contrast, Viking 2 landed on a flat, almost featureless plain. From radio signals, scientists knew the latitude/longitude coordinates of the spacecraft, but couldn't match the coordinates to the actual surface of the planet.
Using a super-resolution imaging technique that exaggerates features on the surface of the planet and by painstakingly counting boulders on the horizon in photographs taken from the Viking 2, Stooke and an undergraduate student, Wallace Chu, were able to pinpoint precisely where the spacecraft landed and match the latitude/longitude grid to the surface.
Since September, a new spacecraft, the Mars Global Surveyor, has been orbiting Mars in an effort to map the planet more precisely. Sometime over the next two years, NASA will attempt to photograph the Viking 2 landing area where Stooke believes it should be. "That will be the ultimate test of our accuracy," says Stooke.
Sue Abel, Department of Communications & Public Affairs