Tucson AZ (SPX) Jun 09, 2010
A geologic mapping project using NASA spacecraft data offers new evidence that expansive lakes existed long ago on Mars. The research points to a series of sedimentary deposits consistent with what would relate to large standing bodies of water in Hellas Planitia located in the southern hemisphere of Mars, said by Dr.Leslie Bleamaster, research scientist at the Planetary Science Institute.
Fine-layered outcrops around the eastern rim of Hellas have been interpreted as a series of sedimentary deposits resulting from erosion and transport of highland rim materials into a basin-wide standing body of water, Bleamaster said.
Hellas basin, more than 2,000 km across and 8 km deep, is the largest recognized impact structure on the Martian surface, he said.
The mapping project reinforces earlier research that initially proposed Hellas-wide lakes citing different evidence in the west, he said. "This mapping makes geologic interpretations consistent with previous studies, and constrains the timing of these putative lakes to the early-middle Noachian period on Mars, between 4.5 and 3.5 billion years ago," he said.
A systematic search of high-resolution images revealed that eastern Hellas Planitia, where the fine-layered floor deposits were discovered, is unique in nature representing a confluence between sedimentary sources and sinks.
The circum-Hellas highlands represent a significant percentage of the southern hemisphere of Mars and have served as a locus for volcanic and sedimentary activity throughout Martian geologic time. Hellas Planitia preserves the materials shed from these highlands and holds the key to further unraveling some of Mars' long held secrets.
"Our mapping and evaluation of landforms and materials of the Hellas region from the basin rim to floor provides further insight into Martian climate regimes and into the abundance, distribution, and flux of volatiles through history," Bleamaster said.
The geologic mapping was published at 1:1,000,000 scale and used Viking Orbiter, Thermal Emission Imaging System (THEMIS) infrared (IR) and visible (VIS) wavelength, and Mars Orbiter Camera (MOC) narrow-angle images, combined with Mars Orbiter Laser Altimeter (MOLA) topographic data, to characterize the geologic materials and processes that have shaped this region and was supported through NASA's Planetary Geology and Geophysics program.
Share This Article With Planet Earth
Planetary Science Institute
new map and accompanying map pamphlet
Mars News and Information at MarsDaily.com
Lunar Dreams and more
Mars Was Wet But Was It Warm
Moffett Field CA (SPX) Jun 01, 2010
On Mars, water is frozen solid. The average temperature of the Red Planet is negative 55 degrees Celsius (-67 F), and when the temperature rises - the highest recorded temperature is a balmy 20 degrees C (68 F) - this ice turns directly into a gas, skipping the liquid phase entirely because of the low atmospheric pressure. Mars may have had a thicker atmosphere and liquid water on its surf ... read more
|The content herein, unless otherwise known to be public domain, are Copyright 1995-2010 - SpaceDaily. AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA Portal 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 SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement|