Winds predicted to be swirling around and inside Gale Crater, which is where NASA's Curiosity rover landed on Mars. Curiosity's current location is marked with an "X." The rover sits within a broad depression between the mountain dubbed "Mount Sharp" to the southeast and the rim of Gale Crater on Mars.(Photo: NASA/JPL-Caltech/ESA/DLR/FU Berlin/MSSS)
Dust devils have twice whirled over NASA's Curiosity rover, mission
scientists said Thursday in a first weather report from Mars.
The $2.5 billion rover, which landed Aug. 5 on Mars inside Gale Crater, has tracked the Martian weather for the past 90 days.
"Gale
Crater is a very interesting place for winds," says mission scientist
Claire Newman of Ashima Research in Pasadena, Calif. After examining
wind speed and direction, the team found that wind swirls in a "moat"
around the mountain in the center of the crater, informally designated
as Mount Sharp.
Dust devils seem to occur in mornings, though
rarely, as the Martian air, less than 1% as thick as Earth's atmosphere,
grows warmer. Sudden pressure drops and wind direction shifts accompany
the dust devils. Manuel de la Torre Juarez of NASA's Jet Propulsion
Laboratory in Pasadena says two dust devils have passed over the rover.
"It's
sort of mid-October on Mars," JPL's Ashwin Vasavada says. Temperatures
range from -130 F at night to above 0 during the day, he says. Because
the rover rests on the southern hemisphere of Mars, temperatures have
grown warmer and the atmosphere thicker, as carbon dioxide frozen as
ice melts on the planet's South Pole with spring's approach.
Radiation
on Mars fluctuates, less during the day and is about half what the
rover experienced while it was in space on its way to Mars. Although far
more intense than radiation on Earth's surface, "absolutely, astronauts
can live in these conditions," says mission scientist Don Hassler of
the Southwest Research Institute in Boulder, Colo. Space station
astronauts see similar radiation doses, for example, Hassler says. "It's
never been a question of 'can we go to Mars'. It is a question of how
can we best protect our astronauts when we get there."
USA Today