Geologists at the Smithsonian's National Air and Space Museum have discovered a large former lake in the highlands of Mars that would cover an area the size of Texas and New Mexico combined, and which overflowed to carve one of that planet's largest valleys. The findings will appear in the June 21 issue of the journal Science.
The flood channel, Ma'adim Vallis, is more than 550 miles long and up to 6,900 feet deep, making it larger than Earth's Grand Canyon.
"Imagine more than five times the volume of water in the Great Lakes being released in a single flood, and you'll have a sense of the scale of this event," said Ross Irwin, a geologist in the museum's Center for Earth and Planetary Studies (CEPS) and the paper's lead author.
Mars is now a cold desert planet but its many dry valleys could indicate that water once flowed on its surface. Recent results from the Mars Odyssey spacecraft have found evidence of water trapped in the near surface of the polar regions.
"The size of this lake-1,400 miles long-suggests Mars was warmer and wetter than previously thought," said Robert Craddock, a CEPS geologist and co-author of the paper.
Former lakes are considered the most likely places to preserve the record of any past Martian life. Calm water would allow sediments to be deposited slowly, preventing small organisms from being destroyed.
The source of water to carve the flood channel had long been a mystery to scientists, who had known very little about Mars' topography prior to the Mars Global Surveyor mission, which has been orbiting Mars since 1997.
Detailed elevation data from the Mars Global Surveyor shows the large valley originated nearly full-size at a ridge, much like the spillway of a dam. Late in the lake's history, rising water levels overflowed the lake basin rim, releasing the huge flood as the river cut into this former dividing ridge. What remained was "some of the best geological evidence for a lake found to date on Mars, including clear indications of the former shoreline," Irwin says.
Two other smaller lake basins were identified in the region by paper co-author Alan Howard, a geologist at the University of Virginia. All three lakes shared the same water level prior to the flood, indicating the possibility of an ancient water table and suggesting the locations of other dry lake basins on Mars. Such information could be important in determining where to land robotic probes in coming years.
Smithsonian National Air and Space Museum
Subscribe To SpaceDaily Express
Mars Odyssey Quenches Researchers' Thirst For Water Data
Los Alamos - Jun 03, 2002
Researchers with the Department of Energy's Los Alamos National Laboratory have determined that Mars has enough water to sustain human exploratory missions.
|The content herein, unless otherwise known to be public domain, are Copyright 1995-2016 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.|