The Perseid meteor shower is one of the most beloved celestial events of the year, particularly in the Northern Hemisphere where summer nights often provide ideal viewing conditions.
This year the annual meteor shower is active between July 17 and August 26. While the peak night, August 11-12, has already passed, the shower is expected to put on a fine show for a night or two before and after, meaning they will still be visible tonight, according to Sky & Telescope magazine.
Tonight, the waxing crescent moon will be around 25 percent full, which means skies will be relatively dark until dawn, ensuring good viewing conditions—depending on the weather where you are of course.
Meteors, colloquially known as “shooting stars,” are the streaks of light produced by tiny pieces of space debris—ranging from about the size of a grain of sand to the size of a pea—burning up in the Earth’s upper atmosphere while traveling at incredibly high speeds. The debris that produces Perseid meteors, for example, travels at around 130,000 miles per hour.
Meteor showers are celestial events during which numerous meteors are seen to originate from a single point in the night sky, known as the radiant.
In the case of the Perseids, the radiant lies in the constellation Perseus, which is named after a hero in ancient Greek mythology who was the son of the deity Zeus and the mortal Danaë.
The debris that produces the Perseids originates from the comet Swift-Tuttle, which is in a 133-year-long orbit around the sun. The comet shed the debris long ago and it is now distributed all along its orbital path.
Every year, Earth passes through this stream of debris, giving rise to the Perseid meteor shower. At the peak of the shower, 50-75 meteors may be visible per hour in clear skies when viewed from rural locations, according to the American Meteor Society.
Which direction do you need to look to see the Perseids?
While the Perseids appear to originate from the constellation Perseus, you do not need to look in this direction see them.
“These ‘shooting stars’ can appear anywhere and everywhere in the sky—you don’t have to look toward the radiant to see them,” Diana Hannikainen, Sky & Telescope‘s observing editor, said in a statement. “So the best direction to watch is wherever your sky is darkest, usually straight up.”
The best time to view them is around 4 a.m. local time when the radiant is highest in a dark sky.