dipper@utastro.UUCP (Debbie Byrd) (10/15/84)
Only one galaxy is visible to the naked eye from the northern hemisphere. We talk about the great galaxy in the constellation Andromeda -- right after this. October 15: The Andromeda Galaxy Only three galaxies are visible to naked-eye observers on Earth. Two of these can be seen from the southern hemisphere -- the Large and Small Magellenic Clouds -- satellite galaxies of the Milky Way. Farther away in space -- but still visible to naked-eye observers in the northern hemisphere -- is the huge spiral Andromeda galaxy, the fraternal twin to our own Milky Way. The Andromeda galaxy is now high in the sky each evening. If you have a starchart, you can find it easily, but be sure to look in a moonless sky, far from city lights. With the naked eye, the galaxy looks like a single star wrapped in a veil of haze. Binoculars show a broadened disk of hazy light. While contemplating this faraway disk, remember that you're really looking at hundreds of billions of stars, their light blurred together over trillions upon trillions of miles of distance. Any beings that live in Andromeda might see our own Milky Way galaxy in exactly the same way. Andromeda closely resembles the Milky Way. Telescopes show that Andromeda has a brilliant central core, with conspicuous spiral arms winding around it. Earlier in this century, we learned Andromeda's speed and direction through space. The entire huge structure was found moving toward our galaxy at the incredible speed of 130 miles per second! Still, at Andromeda's pace -- fast enough to cross the United States in 20 seconds -- it would take a time span nearly as great as the age of the universe to reach us. Script by Deborah Byrd. (c) Copyright 1983, 1984 McDonald Observatory, University of Texas at Austin