The Phoenix Mars Lander, a miner for a heart of ice, has found what researchers say they are sure is frozen water on the fourth planet from the sun.

Phoenix landed in a polar plane, at a far northern latitude of Mars, and the impact of its landing brushed aside loose reddish dirt to reveal whitish material underneath.

Researches suspected it might be ice, the substance for which Phoenix was searching.

But more recently, the scoop on an arm on Phoenix dug into the reddish soil to reveal more white material. And then came the clincher: some of the white material, over days, evaporated.

Had it been, say, salt, that wouldn’t have occurred.

Researchers noted the disappearance of the white material by comparing photos taken several days apart that Phoenix beamed, indirectly, back to Earth.

Some might say it’s only frozen water, so why is this a big deal?

Because it’s on another planet. Because it could indicate that at some earlier time, when Mars was warmer, it could have been liquid water, a key ingredient of life. Because when humans begin voyaging to Mars later in this century, in order to survive and remain alive millions of miles from Earth, they will need water for drinking and as a fuel for their homes, offices and vehicles.

If there is water just beneath the surface in many areas of Mars, that would be invaluable for astronauts when they visit the red planet.

The Big Dig

Phoenix is working fast, because it’s under a death sentence. It has a lifespan measured in months, not years, because soon the freezing 24-hour darkness of the wintertime arctic night will close in, there won’t be sunlight for Phoenix solar arrays to use in making electricity, and the craft slowly will freeze to death.

But so far, it has survived a hair-raising landing and managed to function well, performing, generally, just what researchers asked it to do. (Please see Space & Missile Defense Report, Monday, May 26, 2008, and Monday, June 2, 2008.)

The plucky lander began digging in an area called "Wonderland," taking its first scoop of soil from a polygonal surface feature within the "national park" region that mission scientists have been preserving for science.

The lander’s robotic arm scoop created the new test trench called "Snow White" on June 17, the 22nd Martian day, or sol, after Phoenix landed May 25. Newly planned science activities will resume no earlier than Sol 24 as engineers look into how the spacecraft is handling larger than expected amounts of data.

During Tuesday’s dig, the arm didn’t reach the hard white material, possibly ice, that Phoenix exposed previously in the first trench it dug into the Martian soil.

That’s just what scientists both expected and wanted. The Snow White trench is near the center of a relatively flat hummock, or polygon, named "Cheshire Cat," where scientists predict there will be more soil layers or thicker soil above possible white material.

The Snow White trench is about two centimeters deep (about three-quarters of an inch) and 30 centimeters (about a foot) long. The Phoenix team plans at least one more day of digging deeper into the Snow White trench.

They will study soil structure in the Snow White trench to decide at what depths they will collect samples from a future trench planned for the center of the polygon.

Meanwhile, the Thermal and Evolved-Gas Analyzer (TEGA) instrument continues its ongoing experiment in the first of its eight ovens.

TEGA has eight separate tiny ovens to bake and sniff the soil to look for volatile ingredients, such as water. The baking is performed at three different temperature ranges.

The Phoenix mission is led by Peter Smith of the University of Arizona with project management at JPL and development partnership at Lockheed Martin Corp. [LMT] in Denver. International contributions come from the Canadian Space Agency; the University of Neuchatel, Switzerland; the universities of Copenhagen and Aarhus, Denmark; Max Planck Institute, Germany; and the Finnish Meteorological Institute.