Author: Prakash Sheila
Date: April 2008
NASA's Mars Reconnaissance Orbiter has taken the first-ever image of an active avalanche on Mars. An image of the phenomenon was unintentionally captured by NASA's HiRISE camera on February 19, 2008. The image shows clouds of smoke (some 590 feet, or half the length of a cruise ship, across) billowing near the near the bottom of the ice-capped mountain.
The avalanche occurred near the North Pole, an icy region of Mars that sometimes experiences snowfall. The image marks the first time Mars has been seen in a observable dynamic state.
"It really surprised me," said Daubar Spitale, a member of the HiRISE team at the University of Arizona in Tuscon, in a press release."It's great to see something so dynamic on Mars. A lot of what we see there hasn't changed for millions of years."
Closer inspection of the photograph reveals that at least four distinct avalanches are present. The avalaches were most likely caused by cascades of dust and ice falling from the top of a scarp to the bottom. Scientists speculate that the bulk of the debris was ice.
"If blocks of ice broke loose and fell, we expect the water in them will be changing from solid to gas," said Patrick Russell a collaborator of the HiRISE team.
"We'll be watching to see if blocks and other debris shrink [sic] in size. What we learn could give us a better understanding of one part of the water cycle on Mars."
The cause of the Martian avalanches is still unknown. Avalanches on Mars could be seasonal a possibility that would require a closer inspection of the scarp's behavior through various Martian weather cycles.
"We don't know what set off these landslides," said Russell. "We plan to take more images of the site through the changing Martian seasons to see if this kind of avalanche happens all year or is restricted to early spring."
References:
http://dsc.discovery.com/news/2008/03/04/mars-zoom.html (DiscoveryChannel.com)
http://tinyurl.com/2p79o4(Space.com)
Written by Sheila Prakash
Reviewed by Yangguang Ou, Pooja Ghatalia
Published by Pooja Ghatalia.