Washington, April 16 (ANI): The teams operating NASA's twin Mars rovers is on alert for an upcoming dust storm season, which could be severe enough to minimize activities of the rovers.On April 21, Mars will be at the closest point to the Sun in the planet's 23-month, elliptical orbit. One month later, the planet's equinox will mark the start of summer in Mars' southern hemisphere.
This atmospheric-warming combination makes the coming weeks the most likely time of the Martian year for dust storms severe enough to minimize activities of the rovers.
"Since the rovers are solar powered, the dust in the atmosphere is extremely important to us," said Bill Nelson of NASA's Jet Propulsion Laboratory, Pasadena, California, chief of the engineering team for Spirit and Opportunity.
Unexplained computer reboots by Spirit in the past week are not related to dust's effects on the rover's power supply, but the dust-storm season remains a concern. fter months of relatively clear air, increased haze in March reduced Spirit's daily energy supply by about 20 percent and Opportunity's by about 30 percent. idespread haze resulted from a regional storm that made skies far south of the rovers very dusty.
Conditions at the rovers' sites remained much milder than the worst they have endured.
In July 2007, nearly one Martian year ago, airborne dust blocked more than 99 percent of the direct sunlight at each rover's site.
Observations of changes in the Martian atmosphere by NASA's Mars Reconnaissance Orbiter, which reached Mars in 2006, and NASA's Mars Odyssey, which reached Mars in 2001, are available to supplement the rover's own skywatch.
The Mars Color Imager camera on Mars Reconnaissance Orbiter sees the entire planet every day at resolution comparable to weather satellites around Earth.
"We can identify where dust is rising into the atmosphere and where it is moving from day to day," said Michael Malin of Malin Space Science Systems, San Diego, principal investigator for Mars Color Imager.
"Our historical baseline of observing Martian weather, including data from the Mars Global Surveyor mission from 1998 to 2007, helps us know what to expect," he added. Weather on Mars is more repetitive from year to year than weather on Earth. Global dust events do not occur every Mars year, but if they do occur, they are at this time of year," he explained. (ANI)