The last dust storm on Mars may have killed the Opportunity Rover

NASA expects to soon end efforts to contact the Opportunity Mars rover, silent for more than four months after a major dust storm, but will continue to listen for signals from the spacecraft for months to come.

Opportunity, which has been on Mars since January 2004, last contacted Earth June 10. A powerful globe-spanning dust storm blocked the sun and deprived the rover of solar power, putting it into a low-power mode.

On Sept. 11, NASA’s Jet Propulsion Laboratory said that the optical depth, a measure of the haziness of Martian skies, had dropped to a level low enough to allow enough sunlight to reach the rover for it to generate power. At that point, controllers started an effort known as “active listening” where they transmitted commands to the rover in the event it was unable to revive itself and listened for any transmissions by the rover in response.

After more than a month, Opportunity has not responded to those commands, and that active listening effort will soon end. “We intend to keep pinging Opportunity on a daily basis for at least another week or two,” said Lori Glaze, acting director of NASA’s planetary science division.

While the dust storm moderated temperatures, the return of clear skies means sharp drops in temperature each night. “The batteries may be getting too cold, and that may be too much for the little rover.