The Phoenix Lander deployed by NASA to Mars, which has been taking ice and soil samples for more than 120 days, has discovered something interesting: snow is falling from high up in Mars’ atmosphere, and may even reach the planet’s surface.

The Phoenix shined a laser up towards clouds 2.5 miles up high in the atmosphere, which detected the presence of ice crystals. Due to technological limitations it is unknown whether the very fine ‘diamond dust’ snow actually reaches the surface, but scientists say it is possible, even likely.

Originally sent for a 90 day mission, which has been already extended once to 120 days, the Phoenix Lander is now set to operate ‘indefinitely’, that is until the extreme cold of the Martian winter freezes and cracks its essential parts. The aptly named Phoenix does come with a “Lazarus” feature that potentially allows it to jump back to life when the sun returns, but scientists aren’t counting on it.

The Lander’s main assignment is to look for evidence of former liquid water on the Red Planet’s surface. In that sense it has made some relevant discoveries: using the Phoenix Lander’s on-board chemical laboratory, the NASA team guiding it has detected certain clay-like substances and calcium carbonates (limestone), neither of which could have formed without the presence of liquid water. The lander has found no evidence of it on the surface presently, although it has photographed surface fog and cloud formations.

Jim Whiteway of Toronto’s York University, lead scientist for the Canadian Meteorological Station on the Phoenix says that the snowfall, along with the fog and clouds can hint at the existence of water on the planet, perhaps even in the present. "What this is telling us is that water does rise from the ground to the atmosphere and then precipitates down," he said. "So there is a hydrological cycle on Mars, and now other experts will study the data and try to determine what it all means."

Unfortunately there doesn’t appear to be much time for the Phoenix Lander to perform additional tests; during the Martian summer, the sun is up for most of the 24 h, 40 min day, allowing the Lander to collect plenty of energy to run its equipment through its solar panels. However as winter approaches, there is less and less day time and the temperatures are starting to drop. This means that not only there’s less time for the Phoenix to collect energy, but more of it is being spent on heating for the internal laboratory equipment, which needs a certain level of temperature to operate. It will eventually become to cold for the Phoenix Lander to perform any sort of task.

Nevertheless, the $428 million mission has been declared a success by NASA, having accomplished the majority of its main objectives. The Phoenix is now working long into overtime, and is even so discovering unexpected and interesting facts about the planet, of its past, and the possibility of habitation in the future.