A summertime treat from the heavens, the ice cream of celestial events, the Perseid meteor shower occurs every year in July and August, and is in its most active period now. Created by dust particles burning up in Earth's atmosphere, the streaks of light can be seen all over the night sky, seeming to radiate from a point in the constellation Perseus. If the sky stays clear, conditions tonight will be ideal for meteor viewing. Read on for advice, and don't forget to look up!
When Perseus was a young man, the myth goes, he tried to protect his mother from the unwanted attentions of the king. In his enthusiasm, he inadvertently offered the ruler anything he wanted, even the head of the serpent-haired gorgon, Medusa, which he was then obliged to go and fetch. For his heroics, the ancient Greeks gave Perseus' name to a constellation in the night sky. Today, this arrangement of stars gives its name to a meteor shower – the Perseids – that appears to emanate from the same spot in the sky. Every year, in July and August, these meteors zip through the night, leaving, for an instant, their own snakey trail of light. The Perseids are at their peak now and conditions for viewing are great. With just a little patience, this is what you might see:
Flaming Comet Dust
This year's Perseids shower was predicted to put on a show of 120 meteors per hour, at its climax. What exactly are all those streaks of light? They are nothing more than comet dust, mostly grains the size of sand, but blazing through Earth's atmosphere at incredible speeds. Their source is the comet Swift-Tuttle, which is circling the sun in an orbit of 133 years. Swift-Tuttle is currently far away, but its discarded dust is still with us. At almost the same time each year, our planet passes through this cloud of debris shed by the comet. These mere specks, traveling at 132,000 miles per hour (59 km/s), burn up in spectacular fashion as they enter our atmosphere, creating the streaks of light visible in the night sky.
Near-Peak Perseids Tonight
The 2012 meteor shower began July 17 and will last through August 24, reaching its absolute peak on the night of August 11-12. However, the waning crescent moon will shrink even further tonight, meaning less moonlight and even better viewing conditions—so it's very much still worth getting out there. No worries if you've already got dinner plans this evening: the meteors, or “shooting stars”, are most visible after midnight. Just before dawn is best of all, as the side of the Earth turning toward the sun also turns into the dust cloud, receiving the largest dose of comet debris and, thus, the most meteors.
According to Meteor Showers Online, “The earliest record of Perseid activity comes from the Chinese annals, where it is said that in 36 AD 'more than 100 meteors flew thither in the morning.'" At that time, light pollution would have been less of a nuisance; the streaky sky must have been even more impressive. Still, if you live somewhere with relatively little artificial light, or can escape the urban glow for a night, turn your gaze to the northeastern sky. The meteors will appear to shoot out from the constellation Perseus. This is called the radiant of the meteor shower, and the constellation gives it its name.
Looking about 45 degrees to the left or right of the radiant will give you the best odds. If you look directly at the radiant, the meteors will be heading straight at you and have very short trails. Using binoculars is probably not the best strategy. What you gain in magnification, you'll pay for with a tiny field of view. There's really no telling what part of the sky the next Perseid will streak through, so you're better off keeping your eyes wide open.
The Perseids shower is surely the nicest of the year to take advantage of. They are abundant (particularly in the Northern Hemisphere; for southern observers, the radiant is located below the horizon) and, for those of us hanging around outside in the middle of the night, the August Perseids go down a lot better than January's Quadrantids. Still, if you're not satisfied with your Perseids viewing experience, you'll soon get another chance: the Draconids will be the next meteors to rain down on Earth, in October.
Did you see the Perseids this year? Tell us about it! How many? Did they come close together? Where were you at the time? Did you capture any in photos or video? We hope some of you were able to take in this summer's show!
Find out more: Meteor Shower Calendar http://www.tabwin.com/perseids/calendar.php The Perseid Meteor Show 2012 – Meteor Watch http://www.meteorwatch.org/2012/08/06/the-perseid-meteor-shower-2012/#more-3475 Photos: Amazing Perseid Meteor Shower Displays, from SPACE.com http://www.space.com/12500-photos-perseid-meteor-shower-amazing-images.html August Perseid Meteor Shower Has Long Legacy, Bright Future, SPACE.com http://www.space.com/16915-perseid-meteor-shower-2012-history.html Spacedex presents Perseids Meteor Shower, Info, viewing locations, meetups and more http://www.spacedex.com/perseids/ Suggested Articles: New Evidence for Climate-Changing Cosmic Impact http://blog.mysciencework.com/en/2012/06/19/new-evidence-for-climate-changing-cosmic-impact.html A Practical Guide to Asteroid Mining http://blog.mysciencework.com/en/2012/05/31/a-practical-guide-to-asteroid-mining.html Curiosity Makes It to Mars! http://blog.mysciencework.com/en/2012/08/06/curiosity-makes-it-to-mars.html