A Probing Prelude; April 1999; Scientific American Magazine; by Zorpette; 1 Page(s)

Thanks to a crack in a yoke supporting one of its two solar panels, the Mars Global Surveyor settled into its intended orbit only a month ago, after a year and a half of trajectory adjustments. But as controllers slowly maneuvered the spacecraft to prevent further damage, researchers operating the craft's extensive suite of instruments used the delay to come up with an impressive resume of discoveries about the status and history of water on Mars.

In February, for example, researchers described an image made by the orbiter's camera, which can resolve objects as small as about five meters, or 16 feet (the best resolution of any previous mission was 35 meters). The image showed a deeply cut, sinuous channel in Mars's Nanedi Vallis. Many scientists consider the finding the strongest single piece of evidence to date that water existed on the planet's surface for prolonged periods.