The largest dust storm seen on Mars in more than 2 decades (SN: 7/28/01, p. 53: Craft tracks giant dust storm on Mars) is now beginning to wane, according to data from the Mars Global Surveyor spacecraft. Warmed by dust, the atmosphere is still about 10C hotter than a year ago, says Surveyor scientist Philip Christensen of Arizona State University in Tempe.
In mid-June, Surveyor researchers reported finding dust clouds in the Hellas basin in the south. They later revealed that similar activity had been going in a northerly region. The clouds somehow merged and by June 26 had engulfed most