NASA's Mars Reconnaissance Orbiter and two planet-based explorers are tracking a huge dust storm, offering scientists an opportunity to study the planet's weather like none they've had before.
The regional dust storm was first spotted on Nov. 10 in the planet's southern hemisphere. Though the storm is considered regional, it's big enough that it has lowered air pressure on either side of the planet and increased temperatures on the opposite pole by changing the atmosphere's circulation.
Scientists are waiting to see whether it will develop into a "dust haze" that will engulf the entire planet.
"For the first time since the Viking missions of the 1970s, we are studying a regional dust storm both from orbit and with a weather station on the surface," Rich Zurek, chief Mars scientist at NASA's Jet Propulsion Laboratory, said in a written statement.
The storm has come within 1,400 kilometres of Mars rover Opportunity, which landed on the planet in 2004 and depends on the sun for energy. On the other side of the planet is Curiosity, the nuclear-powered mobile laboratory that landed this year.
If the dust storm expands, the two rovers combined with the Reconnaissance Orbiter should give scientists an unprecedented view.
"One thing we want to learn is why do some Martian dust storms get to this size and stop growing, while others this size keep growing and go global?" Zurek said.
Between Nov. 10 and Nov. 16, the region around the dust storm heated up by about seven degrees Celcius, scientists say. The dust is absorbing sunlight instead of reflecting it, lifting dust above the planet surface and pushing the storm wider.
If the dust engulfs Mars, it could reduce Opportunity's energy supply. Curiosity's power wouldn't be affected but photos from its cameras could be hazy.
-- Los Angeles Times