Showing posts with label Mars. Show all posts
Showing posts with label Mars. Show all posts

Sunday, January 18, 2009

Methane On Mars – Tracks Of Life?


Methane atmospheric abundance spectrometry overlay on Martian surface. Image Credit: NASA

Methane On Mars – Tracks Of Life?

NASA has issued a press release describing the detection of methane gas on Mars and how this may be evidence of life on the red planet.

NASA cautions, "Right now, we do not have enough information to tell whether biology or geology -- or both -- is producing the methane on Mars," said Michael Mumma of NASA's Goddard Space Flight Center in Greenbelt, Md.. "But it does tell us the planet is still alive, at least in a geologic sense. It is as if Mars is challenging us, saying, 'hey, find out what this means.' "

If microscopic Martian life is producing the methane, it likely resides far below the surface where it is warm enough for liquid water to exist. Liquid water is necessary for all known forms of life, as are energy sources and a supply of carbon.

The process of how the methane gas was detected is in itself a good story.

Conceptual animation demonstrating the process of spectroscopy and how it was applied to the discovery of methane in Mars’ atmosphere (click photo). Image Credit: Chris Smith/NASA

This excerpted and edited from the National Aeronautics and Space Administration –

Discovery of Methane Reveals Mars Is Not a Dead Planet
By: Dwayne Brown - NASA, Nancy Neal-Jones, and Bill Steigerwald of the Goddard Space Flight Center - Jan. 15, 2009

WASHINGTON -- A team of NASA and university scientists has achieved the first definitive detection of methane in the atmosphere of Mars. This discovery indicates the planet is either biologically or geologically active.

The team found methane in the Martian atmosphere by carefully observing the planet throughout several Mars years with NASA's Infrared Telescope Facility and the W.M. Keck telescope, both at Mauna Kea, Hawaii. The team used spectrometers on the telescopes to spread the light into its component colors, as a prism separates white light into a rainbow. The team detected three spectral features called absorption lines that together are a definitive signature of methane.

"Methane is quickly destroyed in the Martian atmosphere in a variety of ways, so our discovery of substantial plumes of methane in the northern hemisphere of Mars in 2003 indicates some ongoing process is releasing the gas," said Michael Mumma of NASA's Goddard Space Flight Center in Greenbelt, Md. "At northern mid-summer, methane is released at a rate comparable to that of the massive hydrocarbon seep at Coal Oil Point in Santa Barbara, Calif." Mumma is lead author of a paper describing this research that will appear in Science Express on Thursday.

Methane, four atoms of hydrogen bound to a carbon atom, is the main component of natural gas on Earth. Astrobiologists are interested in these data because organisms release much of Earth's methane as they digest nutrients. However, other purely geological processes, like oxidation of iron, also release methane.
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Animation depicting two processes (geochemical and biological) that may have produced the methane plumes now seen in Mars’ atmosphere (click photo). Image Credit: Susan Twardy/NASA

"We observed and mapped multiple plumes of methane on Mars, one of which released about 19,000 metric tons of methane," said co-author Geronimo Villanueva of the Catholic University of America in Washington. "The plumes were emitted during the warmer seasons, spring and summer, perhaps because ice blocking cracks and fissures vaporized, allowing methane to seep into the Martian air."
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One method to test whether life produced this methane is by measuring isotope ratios.

Isotopes of an element have slightly different chemical properties, and life prefers to use the lighter isotopes.

A chemical called deuterium is a heavier version of hydrogen. Methane and water released on Mars should show distinctive ratios for isotopes of hydrogen and carbon if life was responsible for methane production.

It will take future missions, like NASA's Mars Science Laboratory, to discover the origin of the Martian methane.

Additional photo and animation assets here.
Reference Here>>

Sunday, June 10, 2007

Blue Areas On The Red Orb

Smooth bluish areas on a Martian crater floor could be ponds, according to two scientists. The area is approximately 1 square metre – Image Credit: Ron Levin (as appeared in article, New Scientist)

Blue Areas On The Red Orb

A deeper analysis of the images taken on Mars surface (JPL website) stir the debate on whether there is standing water … puddles of water on Mars.

In a report to be published in the journal IEEE Xplore, R. L. Levin and Daniel Lyddy detail their investigation of possible liquid water ponds on the Martian surface (2007 IEEE Aerospace Applications Conference Proceedings, paper #1376).

Through stereoscopic reconstruction of the images captured by the Mars Rover, Opportunity, Lockheed engineers were able to highlight surface details that just might prove the existence of water on Mars.

Excerpts from the New Scientist –

Mars rover finds "puddles" on the planet's surface
By David Chandler - NewScientist.com news service - 15:33 08 June 2007

The report identifies specific spots that appear to have contained liquid water two years ago, when Opportunity was exploring a crater called Endurance. It is a highly controversial claim, as many scientists believe that liquid water cannot exist on the surface of Mars today because of the planet’s thin atmosphere.

If confirmed, the existence of such ponds would significantly boost the odds that living organisms could survive on or near the surface of Mars, says physicist Ron Levin, the report's lead author, who works in advanced image processing at the aerospace company Lockheed Martin in Arizona.

Along with fellow Lockheed engineer Daniel Lyddy, Levin used images from the Jet Propulsion Laboratory's website. The resulting stereoscopic reconstructions, made from paired images from the Opportunity rover's twin cameras, show bluish features that look perfectly flat. The surfaces are so smooth that the computer could not find any surface details within those areas to match up between the two images.

The imaging shows that the areas occupy the lowest parts of the terrain. They also appear transparent: some features, which Levin says may be submerged rocks or pebbles, can be seen below the plane of the smooth surface.

Smooth surface - The smoothness and transparency of the features could suggest either water or very clear ice, Levin says.

"The surface is incredibly smooth, and the edges are in a plane and all at the same altitude," he says. "If they were ice or some other material, they'd show wear and tear over the surface, there would be rubble or sand or something."
His report was presented at a conference of the Institute of Electrical and Electronics Engineers, and will be published later this year in the institute's proceedings.
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Speedy evaporation? - Levin and other reasearchers, including JPL's Michael Hecht, have published calculations showing the possibility of "micro-environments" where water could linger, but the idea remains controversial.

“The temperatures get plenty warm enough, but the Mars atmosphere is essentially a vacuum," says Phil Christensen of Arizona State University, developer of the Mars rovers' mini-Thermal Emission Spectrometers. That means any water or ice exposed on the surface evaporates or sublimes away almost instantly, he says.
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If there were absolutely no wind, says Christensen, you might build up a stagnant layer of vapour above a liquid surface, preventing it from evaporating too fast. “The problem is, there are winds on Mars… In the real world, I think it's virtually impossible," he told New Scientist.

Simple test - Levin disagrees. He says his analysis shows that there can be wind-free environments at certain times of day in certain protected locations. He thinks that could apply to these small depressions inside the sheltered bowl of Endurance crater, at midday in the Martian summer.

He adds that highly briny water, as is probably found on Mars, could be stable even at much lower temperatures.

Although the rover is now miles away from this site, Levin proposes a simple test that would prove the presence of liquid if similar features are found: use the rover's drill on the surface of the flat area. If it is ice, or any solid material, the drill will leave unmistakable markings, but if it is liquid there should be no trace of the drill's activity.
Reference Here>>