THE SKY THIS JULY: MILKY WAY AND NORTHERN CROSS MARCH ACROSS SKY

Pinwheels, exploding stars, gigantic explosions, and pretty lights in the sky, these are the things fourth of July celebrations are most noted for. But, you need not wait for the next fourth of July to experience these sights again, they are all around you in the Universe we live in. Ever wonder what it would be like to ride on a pinwheel as it whirls around? No need to wonder, you already live the life.

The galaxy we live in is shaped like a flattened disk and we are about 2/3 of the way out towards the edge. Our solar system lies in the plane of this disk and when we look towards the center of our galaxy we see a luminous band of stars and glowing gas cutting across the sky. We called this luminous band the Milky Way long before we realized what it really was. If we could view our galaxy face on from the vantage point of another galaxy, we would see our galaxy as a giant pinwheel in the sky.

Sometime this summer when the weather forecasters report that a cool front has just swept through the area, take a few moments the next night or two to look up at the sky. Behind these cool fronts are calm, cool, dry air which allows for great views of the night sky. 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 over head 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.

This month finds the summer constellations and the Milky Way returning to our night skies. High in the East-Northeast you will find the bright, white star Vega in the constellation Lyra and low in the Southeast you will find the bright, red star Antares in the constellation Scorpius. Early in the evening there is an interesting grouping of stars in the pattern of a small semi-circle called Corona Borealis (the Crown) directly overhead. As the evening progresses the Milky Way continues its march up in the sky and is overhead in the early morning hours. By then, Cygnus the Swan (also known as the Northern Cross) flies down the Milky Way. The actual center of our galaxy is in the direction of the constellation Sagittarius in the South. If you own a pair of binoculars look at some of the bright knots of clouds just above Sagittarius. Here you will find bright clouds of stellar nurseries and star formation regions where stars (and maybe planetary systems) are being born.

On Friday, the Earth was at its farthest distance from the Sun for the year at 95.51 million miles (or 152.09 million kilometers). At this distance, it takes the light from the Sun 8 minutes 27 seconds to reach the Earth. But dont worry. Eight minute old photons are just as good as new ones since, according to Einstein, photons never age. Do you live in the city surrounded by bright lights? Dont have any binoculars or a telescope? You can still see the wonders of the Universe by using your computer and the Internet. Want to see what the sky looks like tonight? Download your own planetarium software.

Simply search the Internet with keywords like planetarium software and presto! I found several free software packages to download. If you want to see what the professionals are looking at check out the latest Hubble Space Telescope images compliments of the Space Telescope Science Institute by pointing your internet browser athttp://www.stsci.eduFor a list of all known astronomical resources on the web check out the page athttp://www.stsci.edu/ astroweb/net-www.html.

If you have always dreamed about being an astronomer and you would like to check out what professional astronomers are doing and the current job market, look athttp://www.aas.orgSo keep your head up and the next fourth when someone wants to show you a giant pinwheel in the sky you can say you have already seen the biggest one of all. If you have other questions or comments about this column please send inquires to the Southeast Missourian or email me at cobb@physics.semo.eduDr. Michael Cobb is an astronomer and chairman of the physics department at Southeast Missouri State University.