After about five months of collecting information on whether Mars can sustain life, NASA scientists have started to shut down heaters, scientific instruments and even the robotic arm onboard the Phoenix Mars Lander.

Since the Lander is powered by solar cells and the Mars night grows longer and longer this time of year, scientists are remotely powering down as many parts of the Lander as possible to minimize its energy needs so a few instruments can be kept running for maybe another month, said Chris Lewicki, mission manager of the Phoenix Mars Mission.

"As it gets colder and colder, we need to heat more things on the spacecraft and because the days are shorter and the sun is lower in the sky, we have less power to do it," he told Computerworld. "It definitely is winding down. As with most things with old age, you slow down and go to bed earlier and wake up later. The Lander is like that. It'll have shorter and shorter work days and have less to do."

Once the instruments spend months in the frigid cold, it's doubtful they could ever be fired back up.

Lewicki noted that darkness fell for the first time on the Lander at the end of August and now the nights are seven hours long. By the end of November, nights will last 10 or 11 hours and by April 24 hours. And right now, it's about 40 degrees Fahrenheit inside the Lander. As the heaters are shut down, the inside temperature will eventually drop to minus 85 degrees.

The mission manager said the start of the shutdown process is turning out to be a sad time for the Mars team. After all, the Lander has sent more information back to Earth about the Red Planet than any other mission. The Lander found ice just under the surface of the soil, proving that water - a key element to support life - exists there. Scooping up soil with its robotic arm the Mars Lander has also taken and sent back microscopic images of Martian soil.

The Lander has discovered that snow falls from Martian clouds. The snow, which evaporates before it reaches the ground, falls from clouds about 2.5 miles above the planet's surface.

And between soil tests done in the Lander's wet chemistry set and its eight ovens, evidence has been sent back that shows that Martian soil is much like Earth's. The Martian dirt is very alkaline, with a pH level of between eight and nine. The Lander also found magnesium, sodium, potassium and chloride in the dirt.