Space Satellite Worries? It's More Dangerous for Space Vehicles than You

You probably shouldn’t lose too much sleep about it, according to an Indiana University of Pennsylvania geoscientist.

“Thousands of old satellites, rocket boosters, and pieces of debris orbit the Earth. Many are in orbits that eventually decay due to friction with the very thin uppermost atmosphere,” explains Dr. Kenneth Coles, IUP associate professor of geosciences and director of the IUP planetarium education program.

“When they lose enough energy to fall to Earth, smaller objects burn up in the atmosphere, but very large ones can make it to the ground. NASA and NORAD (the North American Aerospace Defense Command) track a lot of ‘space junk’ and give as much warning as practical of such events.

“Compared to the other perils of everyday life (such as riding in a car) the hazard is very minor for us on the ground, but space junk is a much greater problem in orbit, where collisions can cause considerable damage to a satellite or spacecraft.”

NASA scientists predict that 26 parts of the satellite will survive re-entry into the Earth’s atmosphere. The NASA prediction is that the odds of getting hit by one of these pieces are 1 in 3,200, according to Nicholas Johnson, NASA’s chief orbital debris scientist.

IUP’s Coles has both his bachelor’s and master’s degrees from the California Institute of Technology and a master’s degree and Ph.D. from Columbia University. In addition to teaching geosciences courses, he directs IUP’s planetarium education program. His research interests include astrometry of asteroids and Moon by occultation of stars; eclipses and transits of solar system bodies; and planetarium education.

IUP’s Geoscience Department’s planetarium is nine meters (30 feet) in diameter and houses a 1966 Spitz A3P projector. The planetarium is used extensively in undergraduate instruction, both in introductory astronomy courses and in classes for Earth and space science teaching majors.

Contact Dr. Coles at kcoles@iup.edu