By Paul Rincon
Science reporter, BBC News, The Woodlands, Texas
Scientists say the possible discovery of mud volcanoes on Mars could boost the search for the planet's past life.
If life ever existed on Mars, the evidence could be buried deep below the surface, where it may be warm enough for water to remain in a liquid state.
Mud volcanoes could transport rocks from depths of several kilometres up to the surface, where robotic explorers could reach them.
Details were presented at the Lunar and Planetary Science Conference in Texas.
Using images taken by Nasa's Mars Odyssey spacecraft, Carlton Allen and Dorothy Oehler of Nasa's Johnson Space Center in Houston identified dozens of mounds in the northern plains of Mars which they say bear a striking resemblance to mud volcanoes.
***
more:
http://news.bbc.co.uk/2/hi/science/nature/7966437.stm