THE SKY IN SEPTEMBER: THE SKY THIS SEPTEMBER

Welcome to the sky this September. I hope your summer was restful and now you are ready to get out the telescope and binoculars and start some stargazing.

The astronomy club will have its first meeting of the season on September the 20th in room 121 Rhodes Hall at 7 p.m. All interested parties are invited to attend. Call 651-2172 for more details. We will establish a schedule for the semester and hope to plan public observing sessions. If you are interested in purchasing a small telescope and would like to talk with others interested in the field, make an effort to attend the meeting.

The university is in the process of establishing a modest observatory and is making plans for a grand opening sometime in October. Stay tuned.

Accompanying this column is a star chart showing the brighter stars and constellations that are visible this month. The chart is designed to be held overhead with the horizon markers rotated around as needed. When facing a particular direction, the corresponding horizon marker should be at the bottom. The chart is accurate at 10:00 p.m. near the beginning of the month and around 8:00 p.m. near the end of the month. Constellation names are typed in all capital letters and star names are lower case letters.

The Milky Way doesn't get any better than this. During the month of September the Milky Way is directly overhead. Combined with the clearer and dryer skies of the fall, the Milky Way puts on a spectacular show.

September marks the beginning of fall. The Equinox occurs on the 23rd and this means the whole world will have equal amounts of daylight and nightfall before we start to get shorter days and longer nights.

Not to let the Milky Way go unchallenged, the planet Jupiter makes a grand entrance at sundown springing up from the horizon in the east. Jupiter is by far the brightest object in the September sky. Jupiter is opposite the Sun around the 15th.

The Earth is closest to the outer planets during their opposition and this year happens to be one of the best oppositions for Jupiter. Even a small pair of binoculars will reveal four small moons around Jupiter. They are called the Galilean satellites in honor of Galileo who first used a telescope and discovered the moons.

Finding moons in orbit around another celestial body was a great discovery of the time as it helped disprove the theory that the Earth was the center of the solar system and that objects only orbited around the Earth. The cost for this knowledge was high, however, as Galileo was excommunicated from the church for his findings and was not formally forgiven until 1992.

The Big Dipper constellation is slowly sinking into the northwestern sky while Cassiopeia is rising in the northeast. The only external galaxy visible to the unaided eye in the northern hemisphere (the Andromeda galaxy) is midway up in the east but you will need a more detailed star chart than the one provided here in order to find it.

Also directly overhead are the star Vega and the constellation Cygnus the swan. Early in the morning the planets Venus and Mercury put on a short dance just before the sun comes up as they play tag and catch-up with each other. Venus is the brighter one, but Mercury puts on one of its best shows early this month.

Higher up in the eastern sky at sunrise is the red planet Mars. Not especially bright this season of its orbit but red never the less.

If you have other questions or comments about this column please send inquiries to the Southeast Missourian or email me at cobb@physics.semo.edu