But scientists are getting the best look ever at how the Martian climate and atmosphere work, according to Dr. Albee. That understanding could help in the planning for future missions and provide insights into weather systems on Earth. A snapshot taken by the orbiting Global Surveyor on Oct. 18 shows the Valles Marineris, an area with dust in it that behaves like snow, including avalanches. Displaying photos relayed to Earth by Global Surveyor, image analyst Mike Malin of Malin Space Science System in San Diego, explained that the camera has spotted terrain where surface formations strongly suggest that a kilometer-wide shallow pond of liquid water once stood. He also showed views of a valley deeper and steeper than Earth's Grand Canyon.
Some layers are dark.
Others are bright. Some form cliffs in stair-step fashion. The team now has data from 18 low orbits over Mars' north pole. Scientists hope to find an explanation for this layering as more data accumulate. Another unexpected finding is that, while Surveyor has detected no general magnetic field, Mars does have regions that are magnetized.