 I was a bit confused into which category should my article belongs,so to be in the safer side I posted it in Media category.
The search for life on Mars started decades back. One hundred years ago it was widely believed that there was life on mars. The American astronomer Percival Lowell even produced detailed maps of canals he claimed had been constructed by water-deprived Martians. Then in1960's space probes sent to mars failed to reveal any sign of life, let alone intelligent canal-building life. But the coup de grace came in 1977 when the US space agency NASA landed two Viking spacecraft on the Martian surface with the specific aim of searching for signs of biological activity. Not so much as a bacterium was found. The surface of mars appeared to be a freeze-dried desert, utterly hostile to any form of life.
Various evidences in support to life in Mars has been found.
According
to news released on Monday, 29 September, NASA's Phoenix Mars Lander
has detected snow falling from Martian clouds. Spacecraft soil tests
experiments also have provided evidence of past interaction between
minerals and liquid water, processes that occur on Earth.
A
laser instrument collecting data on how the atmosphere and surface
interact on Mars detected snow from clouds about four kilometres above
the spacecraft’s landing site. The instrument found the snow vaporised
before reaching the ground.
“Nothing
like this view has ever been seen on Mars,” said Jim Whiteway, of York
University, Toronto, lead scientist for the Canadian-supplied
meteorological station on Phoenix. “We’ll be looking for signs that the
snow may even reach the ground.”
Spacecraft soil experiments also have provided dramatic evidence of
past interaction between minerals and liquid water, processes that
occur on Earth.
Since
landing on May 25, Phoenix already has confirmed that a hard subsurface
layer at its far-northern site contains water-ice. Determining whether
that ice ever thaws would help answer whether the environment there has
been favorable for life, a key aim of the mission.
Phoenix data also suggested the presence of calcium carbonate, the main
composition of chalk, and particles that could be clay. Most carbonates
and clays on Earth form only with water on hand.
“We have found carbonate,” said William Boynton, of the University of
Arizona, lead scientist for the Thermal and Evolved Gas Analyser.
“This points toward episodes of interaction with water in the past. We
are still collecting data and have lots of analysis ahead, but we are
making good progress on the big questions we set out for ourselves,”
said Phoenix Principal Investigator Peter Smith of the University of
Arizona, Tucson.
The Phoenix Lander started digging trenches into Martian soil after
touching down near the planet’s north pole on May 25, revealing a white
substance that scientists said was ice in June. Now scientists want to
examine whether that ice ever thaws to assess whether the environment
has been favourable for life, a key aim of the mission.
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