Sunday, August 12, 2012

Public Readings - Perseid meteor shower 2012: Video shows where to look for planetary alignment

Public Readings - Perseid meteor shower 2012 : Video shows where to look for planetary alignment. Sometimes it is good to have a bit of a heads-up when it comes to stargazing, like in the case of the Perseid meteor shower that peaks in the early morning hours of August 12, otherwise one might miss something of interest. In the case of the Perseids, what one could have missed without a mention might have been the planetary alignment of Venus and Jupiter with the crescent moon. But would you know where they were in the night sky?

Science@NASA put together a little video primer that shows you where to look for the planets while viewing the meteors streaking across the sky. All can be seen with the naked eye, but since the planets will appear as mere points of light and relatively motionless against the dark backdrop of space, it might be a plus for the amateur starwatcher to know where they are and just how they line up.

They align first on August 11. As the Perseid meteor shower seems to emanate from the constellation of Perseus (thus the name), the alignment will occur below the central emanation point in the Eastern sky in the early morning, with Venus holding a central position below the center of the dispersal region. Jupiter will be seen further up the sky to the viewer's right, and the crescent moon will finish the alignment in what appears to be roughly a 50 degree angle.

The red giant star Aldebaran can be seen as well just slightly below and to the right of Jupiter.

On August 12, as the meteor shower peaks, the crescent moon, which is waning, moves to place itself in between the two planets, which, given their distances from Earth, appear to be nearly stationary. On the following night -- and last of the alignment -- the crescent moon moves to a position relatively close to Venus but still between the second planet and the fifth.

The Perseid meteor shower is the just one of a number of such showers that occur each year when the Earth moves through the cast-off and debris of passing comets. The Perseids are the result of such debris from the portions of disintegrated material from the comet Swift-Tuttle.

Bill Cooke, spokesman for NASA's Meteoroid Environment Office, predicts that there will be up to 100 meteors crossing the night sky during some hours. "The Perseids always put on a good show," he insists, and tells potential stargazers that the best time to observe the shower is in the early hours just before dawn. He also suggests the best place to view them is away from bright sources of light, noting that rural viewing allows starwatchers to see as many as three times more shooting stars.

As noted, the Perseids reach their peak on August 12, but will continue to appear in the night sky in ever-dwindling numbers up until August 22. (They started shooting across the sky on July 23.) The next shower of meteors will be the Aurigids, which begin nearly a week later on August 28, peaking on September 1.