Planetary scientists looking for water ice on Mars have employed a number of tactics to great success in their search. The Phoenix lander dug it up; orbiting radar measurements have seen it under insulating blankets of debris. (Frozen water sublimates to vapor in Mars's climate and so is not stable when exposed at the surface.)

Now a team of researchers has let meteorite impacts do the digging for them—a paper in this week's Science presents observations of fresh impacts and what they turn up from below the surface.

Using instruments on NASA's Mars Reconnaissance Orbiter (MRO), a group led by Shane Byrne, a planetary scientist at the University of Arizona's Lunar and Planetary Laboratory, found five recent impact craters in the Martian mid-latitudes, near the boundary where subsurface ice is thought to be no longer tenable. All were relatively small, ranging in size from about four to 12 meters across.

A team from NASA, the military and academia has developed and tested a simple solid rocket fuel of fine-grained aluminum and water ice that the researchers say could provide a cleaner alternative to propellants now in use.

The propellant, known as ALICE (for aluminum and ice), showed its stuff by shooting a nine-foot test rocket a quarter of a mile into the sky this month, according to NASA.

Mitat Birkan, program manager for space power and propulsion at the U.S. Air Force Office of Scientific Research, one of the agencies working on the fuel, says that ALICE is more environmentally friendly, before and after burning, than conventional fuel. The only by-products of ALICE combustion, Birkan says, are gaseous hydrogen and relatively innocuous aluminum oxide.

The heavy snowfall in Western states that's been good news for skiers has come with a price: an unusual number of avalanche-related deaths on resort mountains.

Twelve people have died in U.S. avalanches since mid-December, and 10 in Canada, according to statistics kept by avalanche information centers. In the U.S., three of those deaths were "in bound" (within established ski trails) in Utah, Wyoming and California. That's the most in-bound fatalities since 1976, when three skiers at Lake Tahoe's Alpine Meadows resort perished in an avalanche, the New York Times reports today.

Three months after NASA dropped 90 rubber ducks into holes in Greenland’s fastest-moving glacier to track the melting of Arctic ice, there’s no sign of the toys.

The duckies were deposited into moulins (tubular holes) in the Jakobshavn Glacier in mid-September by Alberto Behar, a robotics expert at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. The idea was that the ducks would float along the same channels that melt waters do, and wherever they emerged would reveal the path of the disappearing ice. 

The ducks have Behar’s e-mail address stamped on them, along with the word "reward" in three languages, including Inuit. NASA is offering $100 to the first person who locates a duck, London's Guardian newspaper notes.

So long, Mars Lander.

The NASA robot’s $475-million mission is over, after increasingly cold weather and diminishing sun on Mars got the better of the lander, which relied on sunlight to recharge its solar battery, scientists said yesterday. It hasn’t contacted Earth since November 2.

"We are actually ceasing operations, declaring an end to operations at this point," Barry Goldstein, Phoenix mission project manager at NASA's Jet Propulsion Laboratory in California, told reporters yesterday. "We'll constantly turn on the radio and try to hail Phoenix and see if it's alive, but at this point nobody on the team has any expectations of that happening."

There's another island the size of Manhattan, but this one is a newly broken ice sheath off the Arctic circle.

The Markham Ice Shelf separated from Canada's Ellesmere Island last month, Bloomberg News reports. The split of the 4,500-year-old, 10-story-tall ice shelf, which borders Greenland, dismayed scientists concerned that global warming was the culprit.

"It was a complete shock,'' Luke Copeland, director of the Laboratory for Cryospheric Research at the University of Ottawa, told the newswire. "What was really amazing is that we lose it all in such a short period of time, within just a few days.''