TORONTO - A Canadian-built weather station on NASA's Phoenix Mars Lander has detected snow falling from Martian clouds.

"Nothing like this view has ever been seen on Mars," said Jim Whiteway of York University in Toronto, lead scientist for the Canadian Meteorological Station on Phoenix.

"That is snow falling from the clouds."

"We'll be looking for signs that the snow may even reach the ground," he said.

Data collected show the snow vaporizing before reaching the surface.

A laser instrument, the lidar, designed to gather knowledge of how the atmosphere and surface interact on Mars, detected snow from clouds about four kilometres above the spacecraft's landing site.

The lidar shoots pulses of laser light into the Martian sky, measuring components of the atmosphere such as dust, ground fog and clouds, from the surface up to a range of 20 kilometres.

"We are still collecting data and have lots of analysis ahead but we are making good progress on the big questions we set out for ourselves," said Peter Smith, Phoenix's principal investigator from the University of Arizona, Tucson.

Since landing on May 25, Phoenix has confirmed that a hard subsurface layer at its far-northern site contains water-ice.

Determining whether that ice ever thaws would help answer whether the environment there has been favourable for life, a key aim of the mission.

The meteorological station is a collaboration led by York, in partnership with the University of Alberta, Dalhousie University and European universities and weather agencies.

It is funded by the Canadian Space Agency.