PLANETS OFFER GREAT HOLIDAY SURPRISE

Well it is that time of the year again and most people get something special on December the 25th -- even astronomers! Between 9:30 a.m. and 12:30 p.m. the Midwest will experience the last partial solar eclipse of the millennium. That is right, this is the true last year of the twentieth century as next year will be the first year of the 21st century. We will see about 45 percent of the sun blocked by the moon.

It will seem like an overcast day (like usual) but this one will be caused by the eclipse.

Do not try to look directly at the sun unless you use shade 13 or 14 welder's glass. The safest way to see the eclipse is by observing the image of the sun cast by a small pinhole on the ground or wall. Any small opening will do like the space between leaves in a tree or even one formed by your hand. You will see a definite crescent shaped image.

December also continues to treat us to the spectacle of three planets Venus, Saturn, and Jupiter. Venus is brilliant in the southwest at sunset while Saturn and Jupiter put on a show in the opposite direction in the east. A little later in the evening the mighty constellation Orion joins Saturn and Jupiter making a beautiful site indeed.

Jupiter is by far the brightest object in the sky, even outshining the red star Aldebaran in the constellation Taurus. Some astronomers think of Jupiter as a failed star. Had Jupiter been much bigger we would have been part of a binary star system just like Luke Skywalker in "Star Wars."

The gravitational force of Jupiter is so strong that when another planet tried to form between Jupiter and Mars, it was disrupted so much that we got the asteroid belt instead. Then once they formed, Jupiter's gravitational force nudged them into Earth-crossing orbits. Jupiter's influence is felt throughout the solar system.

Jupiter has no solid surface and is simply a big ball of gas, mostly hydrogen. With no land mass to slow them down, hurricanes, once formed, rage forever. The great red spot is the best example and has been churning around at least 300 years since Galileo first observed it.

Jupiter's four brightest moons are also called the Galilean satellites in honor of Galileo. Many believe these moons represent the best chance for finding life beyond the Earth. These icy mush melons are gently warmed by the tidal forces of Jupiter's gravitational field and scientists think they provide the right stuff to support life.

Being the biggest planet in the solar system does have its down side. You tend to attract the vagabonds and hobos of the solar system disguised as comets and asteroids. A few years ago, Jupiter was peppered by a broken up comet called Shoemaker-Levi.

Jupiter rotates so fast that its cloud tops are spread into long bands, which encircle the planet. These can be seen even with small telescopes in an alternating pattern of salmon and cream bands.

Whatever Jupiter's pedigree, it is a magnificent site in a small telescope, make sure you unwrap this gift.

Mike Cobb is a professor in the physics department at Southeast Missouri State University and can be reached at 651-2172.