Fans of the hot new movie Avatar have been expressing wonder at its scenes of exotic life on a planet far from earth. So far, such is the stuff of fantasy, but could we ever experience anything like this for real? The universe is such a vast and varied place that chances are, advanced forms of extra-terrestrial life exist somewhere, but will we ever detect, let alone see them? Right now, NASA is struggling financially and logistically to send a manned craft to Mars in the near future. With Earth’s budget limited, how much more challenging will it be to send manned craft beyond our solar system, even to the nearest star? The problems of manned space flight over large distances are enormous. Systems must be capable of supporting human life for years, with adequate food, water and a breathable atmosphere. The human body is not designed to function for long periods in weightlessness. Outside of earth’s protective magnetosphere space travelers would need to be shielded from powerful cosmic radiation. Traveling large distances at high speed increases the chance of hitting objects in space. Collision with even tiny rocks could significantly impair the craft. And any major craft failure would most likely be fatal to the crew as it would take too long for a rescue crew to arrive. However, the main problem with space travel is the vast distances to be covered. Current space travel occurs at only a small fraction of the speed of light (about 0.005%), yet even at the speed of light, it would take over four years to reach the nearest star system, Alpha Centauri, 20 years to reach Gliese 581, the nearest extra-solar planet likely to support liquid water, and 2 million years to reach Andromeda, the nearest galaxy. If, at some future date, it were technically possible to travel close to the speed of light, we would run into other problems. According to Einstein’s Special Theory of Relativity, time slows down when you travel close to the speed of light. So you, the traveler, would age more slowly, but the people you leave behind on Earth would age at the normal rate. On venturing out on a long journey to explore the universe, you would have to be prepared to leave all your loved ones behind, knowing you would never see them again. An alternative to human space travel has been proposed: launching self-replicating machines called Dyson probes into space to send back data way into the future. Whether or not any of this comes to pass, though earth-bound, we are all in fact traveling through space, the earth around the sun, the sun around the Milky Way, our galaxy on its path through the vastness of the universe. As Carl Sagan said, “We have always been space travelers.”
Join the Springfield STARS Club on Tuesday, February 23rd at 7:30pm at the Springfield Science Museum for a talk by Glenn Chaple on Small Telescope Astronomy. An amateur astronomer, Chaple writes a monthly column for Astronomy magazine and is the author of books on astronomy. His latest is Guide to the Universe: Outer Planets. Refreshments will be served, and the public is welcome free of charge.
Amanda Jermyn, of Longmeadow, has been a member of the Springfield Stars Club since 2000 and currently serves on the club's board of directors. For more information, visit the Springfield Stars Club Web site at www.reflector.org or call 1(800)336-9054.
Copyright © Amanda Jermyn