Mars probe discovers snow falling on red planet

Mars probe discovers snow falling on red planet

Oct 1 2008

A NASA mission to Mars has discovered evidence of past water at its Martian landing site and spotted falling snow for the first time, scientists reported.

Soil experiments by the space agency's Phoenix lander have discovered the presence of two minerals known to be formed in liquid water.

Scientists identified the minerals as calcium carbonate, found in limestone and chalk, and sheet silicate.  But exactly how that happened remains a mystery.

"It's really kind of all up in the air," said mission scientist William Boynton.

A laser aboard the Phoenix recently detected snow falling from clouds more than two miles above its home in the northern arctic plains. The snow disappeared before reaching the ground.

Phoenix landed in the Martian arctic plains in May on a three-month mission to study whether the environment could be friendly to microbial life. One of its biggest discoveries so far is confirming the presence of ice on the planet.

Scientists long suspected frozen water was buried in the northern plains based on measurements from an orbiting spacecraft. The lander also found that the soil was slightly alkaline and contained important nutrients and minerals.