| Catalyst Online © 2002 Carleton University School of Journalism and Communication URL: http://www.carleton.ca/catalyst/s2.shtml Is there life out there? Visions of water flowing on the surface of Mars have long been confined to the realm of science fiction, but a new study of the Red Planet is showing they may be closer to science fact than previously thought. NASA’s Mars Odyssey spacecraft began orbiting Mars almost five months ago. At the beginning of March, the probe sent back preliminary information showing a high concentration of hydrogen in the south pole, indicating a possible source of frozen water. Scientists are hoping to confirm there is water ice on or under the surface, for if water once ran there, it increases the possibility that microbial Martian life may have evolved in the distant past. "The essential condition for life to appear is liquid water," says Isabelle Tremblay, a systems engineer with the Canadian Space Agency. The search for water is being performed with the gamma ray spectrometer, a sophisticated piece of electronic equipment on Odyssey capable of analyzing the atomic signatures of elements in the Martian soil. All elements, including hydrogen, emit unique gamma rays when they are exposed to solar radiation. Essentially, gamma rays are cosmic fingerprints, and the GRS is a sophisticated magnifying glass. It will look at 20 elements, including:• silicon Hydrogen is the most important, since it is the main element in water. NASA describes the GRS as a "virtual shovel" because it can detect radiation down to approximately one metre below the surface, the place where most scientists expect to find frozen water. "To verify that water exists we need to go below the surface," says Tremblay. "Deep drilling equipment [will be necessary] to dig deeper and find further traces of water in the Martian soil." While Mars is now too cold for anything to survive, some scientists believe ancient Mars (about 3.5 million years ago) had a thick atmosphere of carbon dioxide and was warm and wet enough to have supported life. The large hydrogen reading coming from the south pole which Odyssey is detecting lends credence to that theory. The GRS is under the control of Dr. William Boynton of the University of Arizona. When the first results were sent back from Odyssey, he said that they sent a "whopping large signal" that there is a great deal of hydrogen in Mars' south pole. Previously, scientists were unsure if the polar caps were made up of water ice or frozen carbon dioxide. Beyond simple scientific curiosity, scientists have a more practical reason for hoping to find water: any future manned missions to Mars would be made far simpler and cheaper if there was a source of drinkable water already on the planet. "In the long term the world's space agencies want to send people to Mars," says Tremblay. "The objective is to gather all the information necessary to let humans survive on Mars." Water is heavy and hard to transport, so if a shuttle crew could distill water once it reached Mars, the spacecraft would be much lighter, thus requiring less fuel and being less expensive to send out. The crew would then only have to bring enough water to reach Mars; exploration and the return journey could be provisioned from the planet itself. |