dipper@utastro.UUCP (12/17/84)
It's easy to see satellites in orbit around the Earth moving noiselessly across our night sky. More on what to look for -- in a moment. December 17 Satellites from Earth A listener wrote to ask about those remote, steadily moving lights you sometimes see crossing the night sky. Well, they ARE spaceships -- launched by people of the planet Earth. In other words, those lights are Earth-orbiting satellites -- some doing science from space -- some for communication -- and some military. There are thousands of objects in Earth orbit. You can see a few of them most any evening -- if they're large enough, and if they happen to pass overhead. The best time to look is just after sunset -- or just before sunrise. When the sun is slightly below the horizon, its rays may strike an object that's very high in the sky. The sun can illuminate a satellite so that we can see it pass overhead. From Earth, satellites look like small, steadily moving stars. In the early days of satellites, people kept track of them in orbit by observing them visually as they passed overhead in the sky. That program was called Moonwatch. Nowadays, there are more sophisticated ways to track Earth-orbiting satellites. But it's still fun to spot one in the sky -- to let it carry your imagination along with it until it disappears. Try it come clear, dark evening. Lie on your back looking up. Suddenly you'll see one "star" that's gliding serenely against the background of the others. If it's blinking, it's an airplane. If you hear it, it's an airplane. But if you just see it -- moving steadily and noiselessly -- it's probably a satellite. Script by Deborah Byrd. (c) Copyright 1983, 1984 McDonald Observatory, University of Texas at Austin