Constellations

1. Constellations • A constellation is an area of the sky with specific borders. Most of the time we refer to the brightest stars in that area. • We’ve recognized constellations since about 1200 B.C.E. • Our list of constellations are based on the list made by Claudius Ptolemy, a famous Roman mathematician and astronomer. • The constellations have historically been used as a calendar, and a navigation tool. A trail is left by the space shuttle Discovery that seems to lead to Orion. An old woodcarving shows Ptolemy’s original constellations. Seeing the Summer Triangle set in the west means that winter is coming.

2. Which Constellations Can We See? • As the seasons change, we can see different stars in the night sky. • In the winter in the northern hemisphere, two very visible constellations are Orion and Taurus. • The Little Dipper is always visible in the northern hemisphere. • In the summer, two of the most famous constellations are Cygnus and Lyra. They are setting now. Why? At 9:00, Orion will be visible below Taurus and the moon. His belt is easy to find. As the Earth travels around the sun, different parts of the universe are visible at night. If you look North, You can see Ursa Minor, the Little Dipper. The star at the end of his tail is Polaris, the North Star. A little to the West of the Little Dipper, you can see Cygnus, the Swan, and Lyra, the Lyre. The star Vega is very important to astronomers.

3. A little later, at 9:00, Orion will be visible below Taurus and the moon. His belt is easy to find. Just after sunset, at 7:30, Taurus, the bull, is visible in the East with the moon. In his body the Seven Sisters are visible. If you look North, You can see Ursa Minor, the Little Dipper. The star at the end of his tail is Polaris, the North Star. A little to the West of the Little Dipper, you can see Cygnus, the Swan, and Lyra, the Lyre. The star Vega is very important to astronomers.

4. A trail is left by the space shuttle Discovery that seems to lead to Orion.