PASADENA, Calif. - A powerful dust storm on Mars has worsened and is affecting the twin rovers' operations on the Red Planet, mission scientists say.
The storm, which has been brewing for a week, has partially blocked the sun. The rovers Spirit and Opportunity, which have solar panels, rely on sunlight to charge their batteries.
Scientists maintain that the robots, which are used to operating at low power levels, are not in danger.
"The storm is affecting both rovers and reducing the power levels on Opportunity," project manager John Callas of NASA's Jet Propulsion Laboratory said in a statement posted Tuesday on the space agency's Web site.
Solar array energy on Opportunity dropped from 765 watt-hours to 402 watt-hours as dust levels increased over the past week. The rover scaled back operations on June 30 to conserve energy.
The storm has already postponed Opportunity's descent into Victoria Crater to learn more about the planet's geologic past. Scientists hoped to send the rover into the crater this weekend, but unfavorable weather has delayed the entry until at least July 13.
The regional storm is the worst to hit the rovers since they landed on opposite ends of Mars in 2004, and scientists expect the storm to last for at least another week.
The highest dust activity is centered near Opportunity. However, weather data show the storm might have peaked, meaning the worst could be behind the rovers.
