In this artist conception, the Phoenix Mars Lander, which launched in August 2007 and the first project in NASA’s Mars Scout missions, landed on Mars on May 25, 2008. (UPI Photo/NASA)
WASHINGTON, Sept. 29 (UPI) — The U.S. space agency says its Phoenix Mars Lander has detected snow falling from Martian clouds, vaporizing before reaching the planet’s surface.
And the National Aeronautics and Space Administration says that, plus soil test experiments, have proven evidence of past interaction between minerals and liquid water — both processes that occur on Earth.
“A laser instrument designed to gather knowledge of how the atmosphere and surface interact on Mars detected snow from clouds about 2.5 miles above the spacecraft’s landing site,” NASA said, adding data shows the snow vaporizing before reaching the ground.
“Nothing like this view has ever been seen on Mars,” said Jim Whiteway, of Canada’s York University, the lead scientist for the Canadian-supplied Meteorological Station on Phoenix. “We’ll be looking for signs that the snow may even reach the ground.”
Since landing May 25, Phoenix has also confirmed a hard subsurface layer at its far-northern site contains water-ice. NASA said determining whether that ice ever thaws will help answer whether the environment there has been favorable for life, a key aim of the mission.
Published: Sept. 29, 2008 at 3:40 PM
Canadian laser gadget finds snow in Martian sky
OTTAWA – Trust a Canadian weather instrument to find snow. Even on Mars.
A Canadian university’s laser aboard a NASA Mars lander has detected snow falling from Martian clouds about four kilometres above the landing site, and vaporizing before reaching the ground.
“Nothing like this has ever been seen on Mars,” said Jim Whiteway, of York University in Toronto, the lead scientist for the Canadian weather station on the Mars Phoenix lander. “We’ll be looking for signs that the snow may even reach the ground.”
Mars Phoenix landed in May at the edge of the Martian Arctic to investigate the soil, and especially to dig for water, in the form of ice.
Ice appears and disappears near the Martian North Pole as the seasons change. But how the moisture moves around is unclear, especially as Mars has very little atmosphere – less than one per cent of what Earth has.
Canada’s share of Phoenix includes lidar, a cousin of radar that uses lasers to scan the sky. Until now, it had found clouds, fog and blowing sand.
Mars Phoenix landed when the weather was warmer (though still below freezing) and the air was absorbing water from the surface, Whiteway said Monday.
Now, as Martian winter approaches, “it’s condensing in the atmosphere . . . and we’ve started to see frost, ground fog and clouds.”
Photos from the little robot show fluffy clouds drifting across the horizon each morning. And lidar’s beam shows that inside those clouds, cascades of the heaviest ice crystals are falling inside the cloud.
“So that is snow, falling from the clouds, and we’re going to be watching very closely over the next month for evidence that the snow is actually landing on the surface.”
The next month may be all the team gets. Phoenix runs on solar power, and the sun will soon set for about three months, leaving the robot to freeze in the dark. It probably won’t survive.
Nevertheless, the chief scientist for Mars Phoenix, Peter Smith of the University of Arizona, is happy.
“The atmosphere is a transport mechanism for water-ice and vapour,” he said Monday.
And soil samples have shown more evidence of water: clay-type minerals and calcium carbonate, two minerals that only form in the presence of water. (Calcium carbonate is the stuff in Tums and Rolaids.)
Solid ice is often just five centimetres below the surface of the planet’s northern plains, he said: scrape away some dirt, “and you would find it’s like a skating rink. It’s a very ice-rich environment.”
Mars changes its tilt every few million years, pointing today’s Arctic region toward the sun. Today’s ice might have become warm enough to make the soil wet in the not-too distant past, he added – a possible habitat for life.
The scientists have one more experiment before winter. They hope to set up the robot’s microphone to record what Mars sounds like for the first time.
The weather station is a collaboration led by York University, in partnership with the University of Alberta, Dalhousie University, the University of Aarhus (Denmark), the Finnish Meteorological Institute, MDA Space Missions, and Optech Inc.
Tom Spears , Canwest News Service
Published: Monday, September 29, 2008