Canadian Scientists Find Clues to the Water Cycle on Mars (Forwarded)

Canadian Space Agency
Longueuil, Quebec

July 2, 2009

Canadian Scientists Find Clues to the Water Cycle on Mars

According to the first findings from the Phoenix Mars Lander mission
(published in this week's edition of Science), snow and water-ice clouds
play a crucial role in the exchange of water between the atmosphere and
surface of Mars, which suggests that the Red Planet is even more like Earth
than previously thought.

The surprise discovery of Martian snow in 2008 by the Canadian-built weather
station on NASA's Phoenix Mars lander helps explain how the water cycle on
Mars behaves, especially the seasonal increase of the Martian polar caps in
winter and their consequent shrinking in summer. The Canadian science team's
paper, entitled "Mars Water-Ice Clouds and Precipitation," describes how
water vapour is lofted upwards during the daytime, forming clouds of
ice-crystals low in the atmosphere that resemble cirrus clouds on Earth.
Water then precipitates through the atmosphere at night in the form of snow.

"It's similar to the phenomenon known as 'diamond dust' in the Arctic. If
you look up into the Arctic night sky, you see fine ice crystals falling
softly towards you," said Jim Whiteway, of York University, lead scientist
for Phoenix's Meteorological Station. "You can still see the stars but it is
like a continuous, light snowfall in the form of ice crystals."

Prior to the Phoenix mission, scientists had not anticipated precipitation
on Mars, nor had they predicted that clouds would form as low as they did.
"We knew that the polar ice cap advanced as far south as the Phoenix site in
winter, but we didn't know how the water vapor moved from the atmosphere to
ice on the ground," said Whiteway. "Now we know that it does snow, and that
this is part of the hydrological cycle on Mars."

Canada's participation in the Phoenix mission brought together expertise
from the Canadian Space Agency, private industry and researchers from across
the country. "Phoenix's weather station is a tribute to the talent and
strength of Canada's space community," said Alain Berinstain, Director of
Planetary Exploration and Space Astronomy at the Canadian Space Agency. "It
is no small feat to build a suite of sophisticated science instruments that
must be delicate enough to take very precise measurements, but robust enough
to survive the trip to Mars. Canada's weather station functioned beautifully
throughout the mission in spite of the hostile conditions on the Red Planet,
and produced high-quality data that has allowed Canadian scientists to solve
one more piece of the Martian puzzle."

York University led the Canadian science team with the participation of the
University of Alberta, Dalhousie University, Optech and Natural Resources
Canada (Geological Survey of Canada), with international collaboration from
the Finnish Meteorological Institute. MDA Space Missions was the prime
contractor for the meteorological station, in partnership with Optech. The
Canadian Space Agency invested $37 million for the design, development,
operations and scientific support of the Meteorological Station.

Within hours of landing, Phoenix's Meteorological Station began beaming back
data on the temperature and pressure at the landing site, and measured dust,
clouds and fog in the lower atmosphere. The warmest temperature recorded
during the mission was minus 19.6 degrees Celsius, with the coldest at minus
97.7 degrees Celsius. Canada's lidar instrument on Phoenix (a shoe-boxed
sized laser instrument) probed the Martian atmosphere daily throughout the
mission for a total of approximately 137 hours of operating time (about 1
hour each Martian day), emitting 49 423 600 laser shots. Perched at the top
of the meteorological station's mast, the wind indicator (known as the
"telltale"), contributed by Aarhus University in Denmark, measured wind
speed and direction and detected the presence of several dust devils at the
landing site. Winds at the Phoenix landing site were typically between 3-5
metres/second (11-18 km/h), which increased to an average of about 10 m/s
(36 km/h) during the last 50 sols of the mission, when winter weather
started to set in. The highest recorded wind speed was 16 m/s (58 km/h).

The Canadian science team's paper is available to registered journalists
through Science's SciPak web page, within EurekAlert!'s password protected
section. Visit: http://www.eurekalert.org/jrnls/sci/ . Reporters can also
request a copy through the SciPak team at 202-326-6440.

The Phoenix Mission is led by Principal Investigator Peter H. Smith of the
University of Arizona, supported by a science team of co-investigators, with
project management at NASA's Jet Propulsion Laboratory and development
partnership with Lockheed Martin Space Systems. International contributions
are provided by the Canadian Space Agency; the University of Neuchatel,
Switzerland; the universities of Copenhagen and Aarhus Denmark; the Max
Planck Institute, Germany; and the Finnish Meteorological Institute.

About the Canadian Space Agency

Established in 1989, the CSA coordinates all civil space-related policies
and programs on behalf of the Government of Canada. The CSA directs its
resources and activities through four key thrusts: earth observation, space
science and exploration, satellite communications, and space awareness and
learning. By leveraging international cooperation, the CSA generates
world-class scientific research and industrial development for the benefit
of humanity.

- 30 -

For more information, contact:

Janice Walls
York University Media Relations
416 736 2100 x22101

Media Relations
Canadian Space Agency
450-926-4370