Mishap gives Mars Surveyor ringside seats to giant dust storm
December 9, 1997
A photo of the surface of Mars taken from Global Surveyor
Web posted at: 11:58 p.m. EST (0458 GMT)
SAN FRANCISCO (CNN) -- A mechanical mishap that forced the Mars Global Surveyor to make emergency flight changes is reaping some unexpected benefits, scientists involved in the mission said, including up-close pictures of a dust storm blanketing 20 percent of the planet's surface.
Surveyor has tracked the storm from its beginnings two weeks ago as a small disturbance toward Mars' south pole.
"It is currently about the size of the southern Atlantic. We don't know if it will grow into a global dust storm," Arden Albee, chief scientist on the project, said Monday at a meeting of the American Geophysical Union.
The Global Surveyor arrived to orbit Mars in September, almost unnoticed by the public in the shadow of the Mars Pathfinder mission. It had been hobbled shortly after its November 1996 launch by an equipment mishap, when one of the two arms holding Surveyor's solar panels did not deploy properly.
The problem forced Surveyor, which is carrying an array of sensors and cameras to map and analyze Earth's closest neighbor, to alter its orbit so as not to put too much pressure on the arm.
In its new elliptical orbit, the craft has flown much closer to Mars' surface than originally intended, coming within 75 miles of the surface instead of the planned 250 miles. The redesigned flight "gives us some very significant science that we couldn't have gotten in the normal design," Albee said.
A photo that shows canyons on Mars
"We have canyons which are hardly named which are steeper and deeper than the Grand Canyon." he said. "We'd never have been gutsy enough to design the mission this way."
The flight change means the spacecraft must now fly backward and will not reach its final intended position until March 1999, one year behind schedule.
Mike Malin, responsible for the cameras on Surveyor, said that fortunately for the scientists still monitoring Surveyor's latest pictures, it did not appear the storm would spread over the rest of the planet. In images captured Sunday, the area of dustiness extends from around 35 degrees south all the way to the pole.
Malin, of Malin Space Science Systems in La Jolla, California, said the images are "really changing our understanding of Mars. Our understanding of Mars dust storms and Mars climate will skyrocket."
For example, he said, there are layers of dusty haze about 37 miles up in the northern atmosphere while dust storms are permeating reaches of the southern hemisphere. Although scientists don't yet have an explanation for the observation, it implies there is some sort of global circulation of the planet's atmosphere.
Reuters contributed to this report.