THE SKY THIS MAY: SUMMER CONSTELLATIONS MAKE WAY BACK

Editor's note: The accompanying star 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 p.m. near the beginning of the month and around 8 p.m. near the end of the month. Constellation names are typed in all capital letters and star names are lower case letters.

Well ... April was a disappointing month. Not only were the planets mostly hidden in the Sun's glare but the star constellations were not very notable, and it rained or was cloudy most of the month. Isn't it ironic? May promises to be a better month as the summer constellations begin their journey up from the East and we have two bright planets in the early morning sky.

The most prominent constellations this month are Leo (the lion) and Ursa Major (the big dipper). Both can be seen nearly overhead as the night becomes dark. The big dipper is of course the astronomers' way to find the North Star. Follow the last two stars on the dipper end and they will point to a nondescript star known as the North Star. The star is famous not because of its color or brightness but because it happens to be near the point around which the stars appear to rotate on a daily basis. This point is called the North Celestial Pole and because Polaris (the pole star) is so close, it never moves very much and can always be found in the North.

The summer constellations slowly begin their comeback this month. The bright star Vega can be seen in the northeast at sunset. It is blue-white in color signifying it as a hot star. Vega was made famous in the movie "Contact" because the U.S. got a galactic fax from an advanced civilization living there. Vega is about 8 parsecs away, which translates into about 20 light years. A light year is how far light travels during one year. Light travels at 186,000 miles per second, or around the Earth seven times in one second. So in one year it goes a long way. By astronomical distances though this is still small potatoes because the closest star other than the sun is more than 4 light years away.

Another bright star is Antares in the constellation Scorpius low in the southeast. It has a very red color and will twinkle since it is low in the sky. The same heat waves you see in the summer over the blacktop exist in the atmosphere all the time. Their effect is increased as you look near the horizon making the star twinkle that much more.

Saturday was National Astronomy Day. In lieu of gifts please take time to look around and enjoy the mysteries set before us. Einstein presented his special Theory of Relativity on May 11, 1916. As strange as it seems, no matter how fast you travel, the speed of light coming out of your flashlight always seems to travel at the same speed. People traveling at different speeds seeing the same beam of light all report the speed of light the same. That experimental fact causes scientists to accept reality as described by Einstein that has consequences like: 1) no one (or thing) can ever travel faster than the speed of light, 2) the faster you go the heavier you get and, 3) the faster you go the slower your clock ticks (sounds like middle age to me). If thinking about such things interests you but you don't want a full Ph.D. in physics, check out the Physics of Star Trek course offered this fall at Southeast. It is being offered as part of the University Studies curriculum. In lay terms the course discusses these and other theories like time travel, black holes and such.

Dr. Linda Godwin, local native and Southeast physics graduate and a NASA astronaut, will give a public lecture at 1:30 p.m. Saturday in Dempster Hall. For more information call the Physics department at (573) 651-2167. If you are between the ages of 10-12 and have an interest in astronomy check out the course "Out of This World: Adventures in Astronomy" offered through the Horizons program this summer. It meets from 9 a.m. and noon. Contact the Office of Extended Learning at (573) 651-2189 for more information.

On the morning of May 29, 40 minutes before sunrise, the planets Venus (the brightest) and Saturn are about 1/2 degree (about the size of the Moon) apart in the east. Next month will see the Milky Way emerging from the East at sunset. Let's hope the weatherman cooperates and gives us a few nights of clear skies.

~Dr. Michael Cobb is an astronomer and chairman of the physics department at Southeast Missouri State University. Send your astronomy questions to him at cobb@physics.semo.edu