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Christopher McKay wants to find an alien, and he thinks he knows where to look. The NASA scientist recently spoke as part of a panel about Mars exploration which discussed past research findings and speculated about future manned missions to the Red Planet. A standing-room-only crowd filled the Palmer Howard Amphitheatre Tuesday, March 16, to hear what he, Canadian Space Agency president Marc Garneau and two research scientists had to say.
The frigid fourth planet from the sun is a hot topic right now. The Canadian Space Agency announced it will join the 2007 Phoenix mission to take the first subsurface samples on Mars, two months ago President George W. Bush pledged an extra $12 billion toward a renewed space effort and recent research has increased hopes that we may find traces of life on Mars. For example, panelist and McGill earth and plantary science professor Hojatollah Vali made headlines several years ago when he announced a Martian meteorite contained evidence of biogenetic activity in the form of crystals that could only be created by bacteria, recent McGill research has pointed to places on Mars where we might find alien remains and this winter an American research mission to Mars, Opportunity, confirmed that the Red Planet once contained life's prerequisite, water.
Scientists have speculated for some time that Mars once had water. James Kasting, a panelist and Penn State University geoscientist, displayed photos from the 1976 Viking orbiter of crevice networks such as the Ares Vallis, Nirgal Vallis and Warrego Vallis which bear a striking resemblance to ancient river systems. By comparing these to similar formations on Earth, there is strong geographic evidence that these rivers existed for a significant period of time. For example, the Nanedi Vallis, like its earth equivalent the Grand Canyon, would have taken at least five to six million years of continuous flowing water to form.
Mars would have needed to be considerably warmer than it is now to support water, and methane might have been an important greenhouse gas, said Kasting. Where there is water and methane, there is the possibility of life - specifically, bugs. "If they were there," he said, "they probably still are, buried deep beneath the ground."
A NASA–McGill project in Canada's arctic regions has shownthat this is a possibility. Doing microbiology with a two-ton drill, the team discovered that if they drilled deep into the permafrost, they could pull out micro-organisms that were still alive. They would like to do the same on Mars in 2011, though any alien insects they find would almost certainly be dead. The creatures could have withstood millions of years in Mars's harsh climate, but they could not have survived the constant radiation the planet receives.
Finding a Martian micro-organism in permafrost would have the same ramifications as finding Neanderthals frozen in the high Arctic. Better than fossil evidence, such a discovery would tell scientists what these creatures looked like and, more importantly, would contain DNA coding. This, said NASA scientist Christopher McKay, is where things get exciting.
Currently, he explained, scientists have only one tree of life to work from, and there is much about it that is not understood. For example, of the two microscopic branches, only one causes disease and no one knows why. However, if a Mars expedition brought back a sample of alien DNA, scientists could then start mapping out the genetic and biochemical aspects of a second tree of life. Both scientifically and philosophically, this would tell us much more about ourselves, said McKay. And with sample-return missions to Mars planned for 2007, 2011 and 2014, the possibility of finding out these answers is one small step closer.
A manned mission to Mars, however, is still a giant leap away. The panelists warned the audience that they would not be watching astronauts bound across the Martian surface anytime soon. "It won't be like Apollo [the American space program that sent men to the moon, which was] sort of an aberration - a race way before its time that cost so much that it couldn't be sustained, and when the political motivation for it went away, the whole project went," said McKay. Humans will go to Mars, he predicted, but only when the cost of a manned mission approximates that of today's unmanned ones. At the current rate of technological development he estimated that this will happen in 30 to 40 years.
Any rush to bring an astronaut to Earth's sister planet could have disastrous consequences. Up until now, two thirds of the 37 missions to Mars have failed, including the recent European Space Agency's Beagle 2 probe and the Japanese Nozomi expedition, and only five space craft have successfully landed on the planet.
Why even send people to Mars when robots can do the same job for much less money and much less risk? In part, said Marc Garneau, it would allow for faster decision-making. When the U.S. Martian probe Spirit touched down on the planet, it took several days for scientists to decide to rotate the rover 120 degrees and send it off a different part of the landing platform. As Garneau explained, having scientists on site would reduce such decision-making times from days to minutes. It would also touch something more primitive in the human psyche.
"We're not hell-bent on sending humans to Mars," he said, but explained that humans will eventually land on Mars for much the same reason Hillary and Norgay had to summit Everest or Scott and Shackleton went to the Antarctic. "After all, I can't imagine a scenario where, let's say a hundred years from now we have sent a hundred or two thousand [robotic missions] to Mars and we've learned a huge amount about everything we wanted to know about Mars and then say, 'OK fine, let's move on to something else.' I think at some point humanity will want to have a human presence on the planet, but let's not rush it."
The lecture was sponsored by the Depts. of Anatomy and Cell Biology, Earth and Planetary Sciences, and Geography; the Beatty Memorial Lectures Fund, Canadian Space Agency, and the Faculties of Science and Medicine.