June 5, 2008--The weather report from Mars is mostly sunny, chance of dust, cold, and dry, thanks to light detection and ranging (lidar) technology built by Optech (Toronto, Canada) at the heart of NASA's Phoenix Mars mission. The Phoenix Mars lander made a dramatic landing on the Red Planet on Sunday, May 25th after a journey of 10 months and hundreds of millions of miles through deep space. The first lidar results from Mars arrived late in the evening of May 28th, amid cheers and applause from NASA officials and science team members gathered at Jet Propulsion Laboratory (JPL; Pasadena, CA) and the Science Mission Operations center at the University of Arizona (Tucson, AZ).
The Phoenix lidar was designed and built by Optech in partnership with MDA Space Missions (Brampton, Ontario, Canada) with funding from the Canadian Space Agency. The analytical lidar, which probes the atmosphere above the lander, is the first of its kind to be sent to another world. The Phoenix mission is also the first of its kind, whittled down by NASA from an initial set of over 20 mission proposals, designed to land in the north polar region of Mars to study the atmosphere and look for habitable conditions supporting life (see Phoenix Mars Lander looks for life using photonics).
"The data look great and all aspects of the system are working well," reported Optech founder and chairman Dr. Allan Carswell from the mission operations center. "I send my congratulations along with those of the principal investigator (PI), Peter Smith, to the whole team at Optech who worked so hard to achieve this outstanding success." After decades of pioneering work developing the analytic lidar theory, and following terrestrial test campaigns chasing dust devils in the desert, Carswell was the initial PI of the Canadian contribution to the NASA Phoenix mission, leading the Canadian Science Team and creating the initial design for the lidar system. Allan remains a key participant of the Canadian Science Team, now led by former student Jim Whiteway from York University (York, England).
Optech lidar technology aboard the NASA Phoenix mission is teaching scientists about the Martian climate and in doing so, helps them understand the factors that affect climate change back here on Earth. Said Carswell. "In the days ahead, lidar measurements will be made during both day and night to provide a highly detailed picture of the atmosphere throughout the mission."
Phoenix works like a robotic scientist searching for water in the soil, analyzing the chemical and mineralogical makeup of the terrain, and studying the atmosphere. Canada's meteorological station (MET) sits on the spacecraft's table-like deck. Using the lidar tool and a suite of temperature, wind and pressure sensors, the MET will track daily weather patterns and seasonal climate changes on Mars.
Weather instrument package
The shoebox-sized lidar has a pencil-thin laser that shoots rapid pulses of light into the atmosphere, which bounce off passing clouds and dust overhead. Any light not scattered by particles in the air is reflected back to a 10-cm optical telescope that is part of the lidar system. The data helps determine the composition, movement, and size of clouds and particles above the lander.
To pierce through most of the thin atmosphere, the laser is pointed upward and works at two wavelengths so that it can give accurate measurements of cloud height to within 10 m. The Canadian science team expects to run the laser for 15 minutes four times daily to determine what time of day clouds begin to form around the landing site, and find out if clouds form at various altitudes at certain times of the day. Though it only requires the power of a 30 W light bulb (with a maximum capacity peaking at 40 W), the lidar can shoot 20 km high into the Martian atmosphere.
By scanning and probing the Martian polar sky in such detail from the ground for the first time, researchers will gather information on ice and dust clouds, ground fog, and maybe see a few surprises such as dust devils and sand storms flying across the landing site. Researchers hope to use this unique data from the Red Planet's polar region to create a clearer picture on the inner clockwork of water cycles between surface ice and vapor in the atmosphere.
Mars weather reports and more information about the mission are available at:
Mars JPL/NASA home page
--V.C.
