dipper@utastro.UUCP (Debbie Byrd) (11/01/84)
This is the anniversary of a recent discovery of a mysterious object between the orbits of Saturn and Uranus. More on Chiron -- right after this. November 1 Chiron On this date in the year 1977, a California astronomer named Charles Kowal discovered an unusual object. In a series of photographs, the object showed itself to be moving with respect to the fixed background of stars -- a clue that it resides in our own solar system. The object looked almost like an asteroid, which would show a similar motion with respect to the stars. But the known asteroids don't orbit the sun much beyond the planet Jupiter. This new object was located a billion miles farther out, between the orbits of Saturn and Uranus. As so often happens in science, Charles Kowal had found something completely unexpected. In fact, it was so unexpected that astronomers still aren't sure how to classify it. No similar small body has ever been found in that part of the solar system -- so should they call it a an asteroid? Or was it the remnant of a comet? Or what? Later it was learned that, at its closest point to the sun, the object comes inside Saturn's orbit. At its farthest, it goes outside the orbit of Uranus. But that's about all we know about this one-of-a-kind world, which has been given the name Chiron. Chiron may be the first of a group of small bodies to be discovered in the outer solar system. Strangely enough, another similar world may be Pluto -- whose diameter has been found to only one-quarter that of Earth -- and whose status as a planet is in question. What's certain is that even our own neighborhood -- the solar system -- still contains some surprises. Script by Deborah Byrd. (c) Copyright 1983, 1984 McDonald Observatory, University of Texas at Austin