The image was taken using the Rover's navigation camera as the vehicle navigated a 32-degree uphill climb, the steepest ever for any rover working on Mars.
The Mars Rover “Opportunity” has recorded the exciting image of a Martian dust devil as seen through a valley below the NASA vehicle. The whirling cloud was seen on March 31, looking back at the rover’s tracks which lead up “Knudsen Ridge,” part of the southern edge of “Marathon Valley.” The image was taken using the Rover’s navigation camera as the vehicle navigated a 32-degree uphill climb, the steepest ever for any rover working on Mars.
Although frequently seen by the previous rover, Spirit, from its station at Gusev Crater, dust devils have been an uncommon sight for Opportunity.
The phenomenon is created by a rising, rotating column of air that gets heated by the sun, just as they are on Earth. Once it whirls fast enough it picks up tiny grains of dust, which then makes the whirling vortex visible. Scientists believe that dust devils help shape the global climate of Mars, since, in the planet’s thin atmosphere, they carry out the important role of dust cycling.
The dust devils are also a clue to the Mars climate puzzle. Dust in the martian air during the day reduces the amount of sunlight that makes it through to the planet’s surface. During the night the atmospheric dust warms the surface. Understanding how the dust gets into the thin Mars air through dust devil activity can help in developing Mars climate models.
Some dust devils can rival the size of tornadoes on Earth, rising hundreds of meters into the air. Some have been measured at 12 miles high. “To start a dust devil on Mars you need a convection, a strong updraft” according to University of Alabama in Huntsville atmospheric science graduate Bryce Williams, who said that twice as much convective updraft is needed in the thin atmosphere of the Red plant as what is required on Earth.
The Marathon Valley region of Mars is of interest to scientists due to orbital measurements that suggest the presence of clays. They are eager for Opportunity to study these minerals since they were created through chemical processes with ancient surface water. The clays may offer answers to more of the mysteries of Mars’ what happened to Mars water.
Spirit lost communication with Earth after becoming stuck in a sand trap in 2010. Opportunity has spent the last 12 years on the planet. The mini-tornadoes play an important part in the continued operations of Opportunity, since they occasionally spin over the solar panels of the rover and blow away accumulations of dust. This allows for a power burst to the solar-powered vehicle.
Photo credit NASA Jet Propulsion Laboratory
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