On Mars, all is extreme: Witness the 12-mile-high dust devil
Mars doesn’t have tornadoes. It doesn’t have thunderstorms. But the Red Planet can kick up a truly unholy dust devil.
Such a phenomenon -- 12 miles high in fact -- was photographed last month on the surface of the planet.
“It really is the size of it that is the unique thing,” said Jet Propulsion Laboratory scientist Ashwin Vasavada. “Conditions allowed this single giant vortex to form and survive to suck up dust all the way to that height.”
The sun beats down on the desert-like surface of Mars and -- with the lack of water and the “extremely thin atmosphere” -- convection begins, said Vasavada, deputy project scientist for the Mars Science Laboratory. “Roiling, turbulent air” forms at the planet’s surface in a layer five to 10 miles thick, he added.
These types of conditions can send dust devils spinning, Vasavada said Thursday in an interview with The Times.
Arguably as impressive as the natural phenomenon is the technology that allowed it to be photographed for us to see back on Earth.
The $720-million Mars Reconnaissance Orbiter is the latest orbiter that NASA has sent to Mars. It was launched in August 2005 and began mapping Mars in March 2006, Vasavada said. The mission is managed by the California-based Jet Propulsion Laboratory.
“One of its key capabilities is this camera,” he added, “the size of a big telescope.” The high-tech, high-resolution piece of equipment -- “like a spy camera on Mars” -- allows scientists to see details on the surface of the planet to about 30 centimeters (11.8 inches) across.
From orbit, HiRISE (for High Resolution Imaging Science Experiment, seriously) was able to see the “golf-cart-size rovers” Spirit and Opportunity, Vasavada said, even picking out their tracks.
The camera has helped scientists pinpoint a spot for the upcoming landing of the Curiosity rover, set for Aug. 5. Curiosity is part of the Mars Science Laboratory project, which will follow up on the discovery of clays -- minerals that need liquid water to form -- on Mars.
Reconnaissance’s CRISM (for Compact Reconnaissance Imaging Spectrometer for Mars) revealed to scientists the colors of minerals. And clays were seen at sites all around the planet, particularly in terrain that dated from the earliest 1 billion or 2 billion years of the planet’s existence, Vasavada said.
Curiosity will land at Gale Crater, where a mound exists that the scientist likened to “a book that has chapters from all the major parts of Mars history.”
Studying this mound will help scientists explore theories on the history of the planet -- the “clay area early on,” Vasavada said, with its hints at surface water “and the best chance of supporting life if there ever was life.”
The next, higher layer in the mound is “sulfates” at the point in Mars history when it was drying out. The most recent history, he said, is “characterized by a lot of boring dust.”
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