Observing the Night Sky - Using a Star WheelBefore you head outside, check your local newspaper for the times the Moon and planets will rise. This information is usually on the weather page or under the heading "almanac." If you have a star wheel, also called a planisphere, practice using it indoors before you try to use it in the dark. Star wheels are actually two flat discs fastened together. The bottom disc shows the stars and constellations, with the months of the year printed along its edge. The slightly smaller top disc has the hours of the day printed on its edge and a window to see through to the stars below. To use the star wheel, you line up today's date from the bottom disc with the current time from the top, and the stars visible in your sky will show through the window. |
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| Now comes the tricky part. Stand facing North, which you found with either the North Star or by turning to your right after facing in the direction of the sunset. North is marked on your star wheel, so stand with that arrow pointing down toward the northern horizon in front of you. That hole in the center of the wheel is where the North Star should be. If you look back and forth between your star wheel and the sky straight in front of you, you should start to see some of the same patterns. Don't be discouraged if you don't. It takes some practice before you can easily recognize the patterns of stars as they are outlined on your star wheel or in books. Remember, the people who dreamed up those constellations lived in a very different time! Also, the constellations will probably be a lot bigger than you are expecting, so think big when looking for the patterns. |  |
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Contact:
CyberScientist@onr.navy.mil