Mars Rovers Weather Worst of Dust Storms

Since late June 2007, Mars has been having a series of regional dust storms, which have obscured most of the planet--and the Mars rovers--with dust. The Mars Reconnaissance Orbiter image from June 22, 2007 (top) shows the first in the series of storms. The July 17, 2007 image (bottom) shows a global "veil of dust" encircling the planet. (Image credit: NASA/JPL/Malin Space Science Systems)

This story was updated at 1:35 pm EDT.

The twin rovers on Mars are in good shape today despite widespread dust storms that worsened last week and threatened to cut off solar power to the robotic explorers.

Steve Squyres of Cornell University, the lead scientist for the Mars Exploration Rovers (MER) project, said that both Spirit and Opportunity are in "excellent shape" based on a radio transmission received this morning.

"Both came through the weekend beautifully," Squyres said in a telephone interview. "They were both power positive over the weekend, meaning they were generating more power than they were consuming."

Astronomers measure atmospheric opacity in units of "tau." The lower the tau value, the clearer the sky.

"At its worst, tau was a little over five [for Opportunity]," Meyers told SPACE.com. "It now has dropped down to a little less than four."

Even though the rovers were not designed to weather dust storms of this magnitude, Meyers said mission scientists and engineers are optimistic the rovers will survive the dust storms, which have been raging for nearly a month now. All scientific observations and driving—including a planned descent into Victoria Crater by Opportunity—remain suspended, for now, to conserve power.

Mission scientists will "wait and make sure that the storm doesn't kick back up," Meyers said. "They're going to wait it out a few more days to make sure."

"Right now, we're just keeping both vehicles safe, and we've been very successful with that so far," Squyres said. "We'll just wait and see what Mars does."

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Ker Than is a science writer and children's book author who joined Space.com as a Staff Writer from 2005 to 2007. Ker covered astronomy and human spaceflight while at Space.com, including space shuttle launches, and has authored three science books for kids about earthquakes, stars and black holes. Ker's work has also appeared in National Geographic, Nature News, New Scientist and Sky & Telescope, among others. He earned a bachelor's degree in biology from UC Irvine and a master's degree in science journalism from New York University. Ker is currently the Director of Science Communications at Stanford University.