9781422283684

Night Sky Spectaculars

  exciting sights in  the night sky.   Meteors and comets are among the most

Catching comets Comets take longer to come and go. These days astronomers are not surprised when comets appear because they have usually spotted them in telescopes months before. Most comets pass through the heavens quickly—you can easily notice them changing position among the stars night by night. Not all comets are bright enough to see with the naked eye. In fact, bright comets are quite rare. But stargazers in the late 1990s were fortunate to see very bright comets for two years running. They were Hyakutake in 1996 and Hale-Bopp in 1997. They both became brighter than all but the brightest stars and were truly spectacular.

Usually, the changes that take place in the night sky occur gradually. The constellations , or star patterns, appear and disappear as the months go by. The planets wander slowly against the background of stars. But meteors and comets appear and disappear suddenly. Meteors come and go in seconds. And they may be seen in any part of the sky. Exceptionally bright meteors may glow all the colors of the rainbow and may even explode. We call them fireballs .

Famed physicist Stephen Hawking describes how the Solar System was formed.

This spectacular comet

∆

of 1997, Hale-Bopp, hangs in the western sky just after sunset. It was one of the brightest comets of the twentieth century, as bright as the brightest stars .

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