Despite the devastating loss of the space shuttle Columbia and its seven-person crew two weeks ago, long-term plans for space exploration continue. For NASA, one major focus is the Mars exploration program, and U of T scientists hope to be a part of it.
Among plans for orbiters, landers and rovers, the Mars program includes a new series of scout missions that will draw upon the scientific community at large. One of the four finalists selected by NASA for a 2007 scout craft is MARVEL (Mars Volcanic Emission and Life Scout), which includes a Canadian instrument called MICA (Mars Imager for Clouds and Aerosol).
MICA’s principal investigator is Jim Drummond, a U of T physicist. His collaborators include scientists from other Canadian universities (Toronto, New Brunswick, Waterloo, York) and private industry (COM DEV Ltd. and EMS Technology).
The heart of MICA will be a multi-band camera that would focus on the horizon of the Martian atmosphere immediately after sunset and before dawn. The instrument, which will weigh less than two kilograms, will provide images of clouds and layers of dust by exploiting the fact that light will scatter around the edge of the planet as it blocks the sun during sunset or sunrise, significantly enhancing the visibility of thin Martian clouds.
The role of aerosols in the chemistry of the Martian atmosphere is huge, Drummond explained. “There are planet-wide dust storms where [one] can’t see anything below 22 kilometres. Normally we think about the aerosol in the earth’s atmosphere as having a role in the chemistry. Here we have dust which drives a truck through the physics and chemistry of the atmosphere.”
With earlier observations indicating the presence of clouds and water vapour in the Martian atmosphere, Drummond wants to ask: “Is that all there is? Or is there some larger reservoir somewhere, and if so, does that reservoir interact with the surface system?”
But since carbon dioxide makes up approximately 95 per cent of the Martian atmosphere, co-investigator and U of T physicist Vicky Hipkin said they are not just interested in water vapour clouds but also “carbon dioxide clouds and possibly clouds of mixtures of carbon dioxide and water.”
Along with U of T’s MICA, the MARVEL mission would house two other instruments that can search for previously undetected gases. MARVEL aims to survey the Martian atmosphere for active volcanoes and microbial activity and to study the water cycle on the Red Planet.
“The instrument is designed to make a broad suite of measurements and find things, such as methane, that have not been discovered,” said Hipkin. Methane-producing micro-organisms represent some of the most primitive life forms on earth and they have been found under cold and dry conditions that parallel the Martian environment.
The researchers do not anticipate the Columbia shuttle tragedy will impact the Mars exploration program and feel their scout mission is still an important project. “We are sending…a research class package to look at the atmosphere. In a lot of things, the Martian surface has been looked at exhaustively but the atmosphere has been somewhat neglected and the atmosphere has a great deal of potential to teach us about the planet,” Drummond said.
The 2007 Mars mission finalists are nearly through a $500,000 (US) feasibility study. If selected, Hipkin thinks the MARVEL scout will provide a huge amount of useful data, with “things…to discover in it for years to come, questions that we are not even asking at the moment.”
Photograph by Simon Turnbull
