The Phoenix Lander, expected to last just 90 Martian days, is still exploring the red planet's air, ice and soil many weeks after it was expected to die. More than 130 days after landing near the planet's north pole, the lander has recently discovered snow falling from clouds as winter on northern Mars approaches. VOA's Paul Sisco reports.

After traveling 10 months and 679 million kilometers, NASA's Phoenix probe landed on Mars' northern arctic plain last May. It was intended to be a three month mission.  The probe has recently photographed clouds, hard to see with the naked eye, and unexpectedly detected snow.

"As we move into the Martian winter we've decided to extend the mission further, to try to survive as long as we can," says NASA's Doug McCuistion, who directs the Mars exploration program. "There is an end to this mission because of weather, but we want to see how far we can get into winter (to) understand the climatic processes that occur."

Phoenix is on Mars' northern plain, digging into the soil and sending scientists on Earth a wealth of data and images about the red planet's surface, subsurface and atmosphere.

"Phoenix has done a great job in helping us expand our understanding of water and climatic processes and the water drivers in the climate," says McCuistion. "The significant amount of science data collected by the Phoenix mission will last the science research community for a significant number of years to come."

Phoenix has sent microscopic images of minerals on the Martian surface, and panoramic views of the landing area. "Right away, in the first couple of months of being on the surface we were able to determine that the robotic arm could scrape through the surface soils only a few inches deep and reveal an ice layer," explains the lander's principle investigator, Peter Smith.

That accomplished, it began analyzing soil composition and atmospheric samples, in addition to sending fascinating images of the red planet. "Nearby our landing site is a large crater," says Smith, "and we are actually on the material that was blown out of the crater when it was impacted millions of years ago. If you were to sweep this thin soil layer on what looks like a flat plain, you would find that it is really a more like a skating rink; it's a very ice rich environment."

An instrument that sends pulsing beams into the Martian sky has detected snow falling toward the planet, a surprise to investigators.

Now, the sun is setting on Phoenix, and the science team predicts the lander will likely cease all activity by the end of the year.