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

Kansas City Jewish Community Center shooter: “I was an FBI Informant”
2014 04 24
Kansas City Jewish Community Center shooter: “I was an FBI Informant” …… Which is EXACTLY how we called it when this story broke a few weeks back. We also mentioned that the SPLC, just discarded from the FBI “hate” website… Would be the prime benefactor. Ex-KKK Leader Was Given a New Identity Years Before Shooting Glenn Miller Claims He Was an FBI Informant by ...
Meet AISight – The Artificial Intelligence Software Being Installed on CCTV Networks Globally
2014 04 24
If you thought that CCTV cameras tracking your every move in public was bad enough, you’re going to just love AISight (pronounced “eyesight” of course). The invention of a Houston, Texas based company called BRS Labs (which stands for Behavioral Recognition Systems) is headed by former secret service special agent John Frazzini, and this Orwellian surveillance platform brings artificial intelligence ...
Biofuel Made From Corn Waste Less ‘Green’ Than Gasoline
2014 04 24
Biofuel created from corn waste may not be the clean, eco-friendly oil alternative the United States government is hoping for. A new study has found that fuel generated from harvested corn leftovers creates more greenhouse gases than conventional gasoline — at least in the short term. The fuel under study, called cellulosic ethanol, has been touted in recent years as a ...
Swedes open coffin of 850-year-old king
2014 04 24
Scientists pried open the 850-year-old casket of King Erik the Holy on Wednesday, hoping to find out more about the king, his crown, and his eating habits. "This was a very special occasion, especially considering the importance of Saint Erik religiously in Sweden," Uppsala Cathedral Chaplain Lars Åstrand told The Local. The casket contained the bones of King ...
John Kerry and the Pope set to face off with Jewish Knight Templars on the Temple Mount
2014 04 24
This is the week that supposedly spells the end of the peace process or its end. My money is on a continuation that has no real substance or direction. What’s the alternative? With Passover and Easter over, Secretary Kerry can return to the Middle East crisis. This, after dealing so successfully with crisis in the Ukraine. [Is the author joking? - RIC] With ...
More News »