The 2008 Perseid Meteor Shower

The 2008 Perseid meteor shower peaks on August 12th and it should be a good show.

"The time to look is during the dark hours before dawn on Tuesday, August 12th,"says Bill Cooke of NASA's Meteoroid Environment Office at the Marshall Space Flight Center. "There should be plenty of meteors--perhaps one or two every minute."

Serious meteor hunters will begin their watch early, on Monday evening, August 11th, around 9 pm when Perseus first rises in the northeast. This is the time to look for Perseid Earthgrazers--meteors that approach from the horizon and skim the atmosphere overhead like a stone skipping across the surface of a pond.

"Earthgrazers are long, slow and colorful; they are among the most beautiful of meteors," says Cooke. He cautions that an hour of watching may net only a few of these at most, but seeing even one can make the whole night worthwhile.

The source of the shower is Comet Swift-Tuttle. Although the comet is far away, currently located beyond the orbit of Uranus, a trail of debris from the comet stretches all the way back to Earth. Crossing the trail in August, Earth will be pelted by specks of comet dust hitting the atmosphere at 132,000 mph. At that speed, even a flimsy speck of dust makes a vivid streak of light when it disintegrates--a meteor! Because, Swift-Tuttle's meteors streak out of the constellation Perseus, they are called "Perseids."

For maximum effect, "get away from city lights," Cooke advises. The brightest Perseids can be seen from cities, he allows, but the greater flurry of faint, delicate meteors is visible only from the countryside.

Uranus and Neptune in 2008

Uranus and Neptune spend 2008 in Aquarius and Capricornus, respectively. These are southerly constellations, which never get very high in the sky for people at mid-northern latitudes. So it's important to make the best of the relatively short window of opportunity for viewing them.

Neptune reaches opposition to the Sun on August 15th, and Uranus on November 2nd. These are the dates when the planets rise around sunset and set around sunrise, and reach their highest in the sky in the middle of the night. Neptune is reasonably well placed in the evening sky from August through the end of October, and Uranus from September to early December.

Download a detailed, printable chart for both planets in PDF format.

original source: Sky & Telescope