Definitive Evidence For Ancient Lake On Mars
2009 06 22

ScienceDaily.com

A University of Colorado at Boulder research team has discovered the first definitive evidence of shorelines on Mars, an indication of a deep, ancient lake there and a finding with implications for the discovery of past life on the Red Planet.


This is reconstructed landscape showing the Shalbatana lake on Mars as it may have looked roughly 3.4 billion years ago. Data used in reconstruction are from NASA and the European Space Agency. (Credit: G. Di Achille, University of Colorado)


Estimated to be more than 3 billion years old, the lake appears to have covered as much as 80 square miles and was up to 1,500 feet deep -- roughly the equivalent of Lake Champlain bordering the United States and Canada, said CU-Boulder Research Associate Gaetano Di Achille, who led the study. The shoreline evidence, found along a broad delta, included a series of alternating ridges and troughs thought to be surviving remnants of beach deposits.

"This is the first unambiguous evidence of shorelines on the surface of Mars," said Di Achille. "The identification of the shorelines and accompanying geological evidence allows us to calculate the size and volume of the lake, which appears to have formed about 3.4 billion years ago."

A paper on the subject by Di Achille, CU-Boulder Assistant Professor Brian Hynek and CU-Boulder Research Associate Mindi Searls, all of the Laboratory for Atmospheric and Space Physics, has been published online in Geophysical Research Letters, a publication of the American Geophysical Union.

Images used for the study were taken by a high-powered camera known as the High Resolution Imaging Science Experiment, or HiRISE. Riding on NASA's Mars Reconnaissance Orbiter, HiRISE can resolve features on the surface down to one meter in size from its orbit 200 miles above Mars.

An analysis of the HiRISE images indicate that water carved a 30-mile-long canyon that opened up into a valley, depositing sediment that formed a large delta. This delta and others surrounding the basin imply the existence of a large, long-lived lake, said Hynek, also an assistant professor in CU-Boulder's geological sciences department. The lake bed is located within a much larger valley known as the Shalbatana Vallis.

"Finding shorelines is a Holy Grail of sorts to us," said Hynek.

In addition, the evidence shows the lake existed during a time when Mars is generally believed to have been cold and dry, which is at odds with current theories proposed by many planetary scientists, he said. "Not only does this research prove there was a long-lived lake system on Mars, but we can see that the lake formed after the warm, wet period is thought to have dissipated."

Planetary scientists think the oldest surfaces on Mars formed during the wet and warm Noachan epoch from about 4.1 billion to 3.7 billion years ago that featured a bombardment of large meteors and extensive flooding.

The newly discovered lake is believed to have formed during the Hesperian epoch and postdates the end of the warm and wet period on Mars by 300 million years, according to the study.

The deltas adjacent to the lake are of high interest to planetary scientists because deltas on Earth rapidly bury organic carbon and other biomarkers of life, according to Hynek. Most astrobiologists believe any present indications of life on Mars will be discovered in the form of subterranean microorganisms.

But in the past, lakes on Mars would have provided cozy surface habitats rich in nutrients for such microbes, Hynek said.

The retreat of the lake apparently was rapid enough to prevent the formation of additional, lower shorelines, said Di Achille. The lake probably either evaporated or froze over with the ice slowly turning to water vapor and disappearing during a period of abrupt climate change, according to the study.

Di Achille said the newly discovered pristine lake bed and delta deposits would be would be a prime target for a future landing mission to Mars in search of evidence of past life.

"On Earth, deltas and lakes are excellent collectors and preservers of signs of past life," said Di Achille. "If life ever arose on Mars, deltas may be the key to unlocking Mars' biological past."

Adapted from materials provided by University of Colorado at Boulder.

Article from: ScienceDaily.com



Related Articles
Mars May Still Be A Living Planet, Methane In Atmosphere Reveals
Is there a Life On Mars Conspiracy?
Mars: Windy, Wet And Wild: Victoria Crater Unveils More Of Mars' Geologic Past
Mars explorer says we'll find life on other planets within 10 years
Should Mars be treated like a wildlife preserve?


Latest News from our Front Page

The War Against Whites Is Massively Incentivized
2014 08 28
The war on Whites is getting increasingly obvious, to the point that a very mainstream source, Congressman Mo Brooks, stated it and then refused to back down. This war is being carried on with a number of very potent weapons. At TOO we have stressed the moral onslaught which has inculcated guilt among legions of Whites for actions that have occurred ...
Study Offers Clues to Arctic Mystery: Paleo-Eskimos’ Abrupt Extinction
2014 08 28
Seven hundred years ago, the Dorset people disappeared from the Arctic. The last of the Paleo-Eskimos, the Dorset culture had dominated eastern Canada and Greenland for centuries, hunting seal and walrus through holes in the ice and practicing shamanistic rituals with ornate carvings and masks. Then, they promptly ceased to exist. Modern archaeologists have scoured troves of Arctic artifacts, searching for ...
Lois Lerner’s IRS Blackberry Destroyed After Federal Probe
2014 08 28
The IRS destroyed former Lois Lerner’s BlackBerry after Congress started probing whether the IRS was targeting conservative groups. Lerner was director of the Exempt Organizations Division of the IRS. A sworn declaration of Thomas Kane, a senior IRS lawyer, reveals that in June 2012, the IT department of the IRS wiped any sensitive or proprietary information from the BlackBerry in ...
White Marine Beaten by Black Mob in Michael Brown ‘Revenge’ Attack
2014 08 28
Police refuse to treat incident as a hate crime A white Marine was left in an induced coma after a group of black men brutally beat him as part of a revenge attack in response to the killing of 18-year-old Michael Brown in Ferguson, Missouri. The incident began at West Point Waffle House in Mississippi on Saturday morning at around 1am. With ...
Study: Exposure to Endocrine disrupting Chemicals Can Affect Future Generations
2014 08 28
Scientists have known that toxic effects of substances known as endocrine disrupting chemicals (EDCs), found in both natural and human-made materials, can pass from one generation to the next. New research shows that females with an ancestral exposure to EDC may show especially adverse reactions to stress. According to a new study by researchers from The University of Texas at Austin ...
More News »