Mars Exploration News  
Shiny Rock Coating May Hold Key To Martian Life

The nature of desert varnish has intrigued scientists since the mid-19th century. Image credit: Imperial College London
by Staff Writers
London, England (SPX) Jul 06, 2006
A mysterious shiny coating found on rocks in many of Earth's most arid environments could reveal whether life once existed on Mars. Research published in the July edition of the journal Geology suggests the dark coating known as desert varnish creates a record of life around it by binding traces of DNA, amino acids and other organic compounds to desert rocks.

Therefore, samples of Martian desert varnish could show whether there has been life on the red planet at any stage over the last 4.5 billion years.

The researchers said they hope their findings will encourage planners of future Mars sample-return missions to include desert varnish to their list of target substances.

The source of the varnish, which looks like it has been painted onto the rocks, has intrigued scientists since the mid-19th century. British biologist Charles Darwin became so fascinated with the material he asked Swedish geochemist Jons Berzelius to investigate it.

Previous research had suggested its dark color resulted from the presence of manganese oxide, and any traces of life found within the varnish probably originated from biological processes caused by microbes in the mineral.

The new research, however, used a battery of techniques - including high resolution electron microscopy - to show that any traces of life in the varnish do not come from microbes in MnO.

Instead, the research reveals, the most important mineral in the varnish is silica, which means biological processes are not significant in the coating's formation. On desert rock surfaces, silica is dissolved from other minerals and then gels together to form a glaze, trapping organic traces from its surroundings.

Randall Perry of Imperial College London, the lead author of the research, explained that because life is not involved in desert varnish formation, it can serve as an indicator of whether life was present or absent in the local environment.

"If silica exists in varnish-like coatings in Martian deserts or caves, then it may entomb ancient microbes or chemical signatures of previous life there, too," Perry said. "Desert varnish forms over tens of thousands of years and the deepest, oldest layers in the varnish may have formed in very different conditions than the shallowest, youngest layer."

"These lustrous chroniclers of the local surroundings can provide a window back in time," he added. "Martian desert varnish would contain a fascinating chronology of the Martian setting."

Perry's colleagues included researchers at the University of Auckland, New Zealand; the University Wisconsin-Parkside and the University of Washington in the United States, and the University of Nottingham Trent in the United Kingdom.

Community
Email This Article
Comment On This Article

Related Links
- Mars News and Information at MarsDaily.com
Lunar Dreams and more



Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News


Victoria On The Horizon For Opportunity
Pasadena CA (SPX) Jul 06, 2006
This image from the Mars Orbiter Camera aboard the Mars Global Surveyor shows Opportunity's position as it approaches Beagle crater on the way to Victoria crater. North is to the left. Opportunity's locations at Martian mission days, or sols, 804 (April 29) and 855 (June 20) are marked, as are the left and right edges of the rim of Victoria from the rover's point of view.









  • Could NASA Get To Pluto Faster? Space Expert Says Yes - By Thinking Nuclear
  • NASA plans to send new robot to Jupiter
  • Los Alamos Hopes To Lead New Era Of Nuclear Space Tranportion With Jovian Mission
  • Boeing Selects Leader for Nuclear Space Systems Program

  • SMART 1 Photographs Kepler Crater Up Close
  • Mysterious Lunar Swirls
  • SMART-1 Maneuvers Prepare For Mission End
  • GMV To Provide Mission Planning Software For Lunar Reconnaissance Orbiter

  • South Korea Picking Astronauts
  • USA Partners With Pioneer Aerospace On CEV
  • Jules Verne ATV Passes Acoustic Tests
  • NASA Names Shuttle Successor Rocket Ares

  • IAU Approves Names For Two Small Plutonian Moons
  • Three Trojan Asteroids Share Neptune Orbit
  • New Horizons Crosses The Asteroid Belt
  • Trio Of Neptunes And Their Belt

  • Gas Giants Consistently Larger Than Their Moons
  • Two Great Jovian Storms Converging
  • The Pull Of Jupiter
  • Hubble Takes Sharpest Shot Yet Of New Red Spot On Jupiter

  • Venus Express Spies Double Vortex
  • Venus Express Commissioning Phase Completed
  • Venus Express Reaches Final Mission Orbit
  • Venus Express Transmits First Images

  • Cassini Uncovering More Secrets Of Saturn Rings
  • Enceladus Exudes Air Of Mystery
  • Cassini Shines At Mission Halfway Point
  • NASA Makes Movies Of Saturn Moons In Motion

  • Research Office Helps Excite Oxygen to Make Laser
  • Falcon Supercomputer To Solve Problems
  • First Teraflop Class Supercomputer Decommissioned After 10 Years Service
  • AMPAC-ISP To Supply Loral With Thrusters For Telstar 11N Satellite

  • The content herein, unless otherwise known to be public domain, are Copyright 1995-2006 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA PortalReports are copyright European Space Agency. All NASA sourced material is public domain. Additionalcopyrights 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