Thursday, August 05, 2004

Meteor Showers Peaking

Meteor Showers Peaking
by Dave Adalian

"Reliable" is a word not usually associated with meteors, but that’s exactly how astronomers like to describe the Perseid meteor shower that peaks next week.

Conditions for meteor viewing should be just about perfect Wednesday night, Aug. 11, with a thin crescent of a Moon not rising until the wee hours. The actual peak of the shower will come about four hours after midnight on the morning of August 12, and midnight to dawn will give the best views. But, the Perseid shower’s peak is a wide one so beautiful displays may be available from dark skies as soon as the Sun has completely disappeared.

This peak is so wide many meteors are visible a night or two before and after the peak. Meteors from this shower began appearing in late July, so those eager to get started might even catch a handful tonight before moonrise.

Average counts for experienced meteor observers have been in the range of 60 meteors an hour for the Perseids during the hours between midnight and dawn on the night of the peak. Those who predict the intensity of meteor showers say this year might bring a higher rate since Jupiter has perturbed the stream of debris that causes the shower, pushing it closer to Earth.

As always, the darker the sky above, the better the viewing below, so the best places to observe meteor falls are in the countryside, foothills or mountains.

Brighter members of the shower will probably be visible even under city lights. So, too, will be several of the brighter constellations, including the Teapot of Sagittarius in the south and to its right the scorpion of Scorpius. Overhead is the bright star Vega in the constellation Lyra. Vega, along with Deneb and Altair, create the brilliant Summer Triangle.

North is the easily recognizable Big Dipper of Ursa Major and to its right the North Star marks the end of the Little Dipper’s handle. If city skies are dark enough all seven of the Little Dipper’s dim stars might be available to the naked eye.

To the Little Dipper’s right is the bright W asterism of the constellation Cassiopeia and below that is Perseus, the star-studded constellation for which the Perseid meteor shower is named. The point where the Perseids appear to originate is between these two constellations, and around this area is the best direction for Perseid hunters to gaze.


This column appeared originally in the Visalia (Calif.) Times-Delta on Aug. 5, 2004.