Mineral evidence of Mars' water environment discovered

BEIJING, Dec. 19 (Xinhuanet) -- A NASA¡¯s orbiting spacecraft
has discovered the mineral evidence for a water environment capable of
supporting life on Mars, according to media reports Friday.

Deposits of the 3.6 billion-year-old carbonate were
spotted in the bedrock at the edge of a 930-mile-wide (1,490-km-wide) crater.
The deposits are about the size of football fields and are visible in images
taken by the Mars Reconnaissance Orbiter.

It is the first time scientists have found a site
where carbonate formed.

"Obviously this is very exciting," said John Mustard
of Brown University in Rhode Island. "It's white -- it's a bulbous, crusty
material."

Carbonate is formed in neutral or alkaline water. It
dissolves quickly in acid, so its discovery counters the theory that all water
on Mars was at one time acidic.

The region "would have really been a clement, benign
environment for early Martian life," said Bethany Ehlmann of Brown University.

Carbonate previously had been found in minuscule
amounts in soil samples provided by the Phoenix Mars Lander, Martian dust and
Martian meteorites on Earth.

(Agencies)