Amateur astronomers, space junkies, people with kids, or anyone who loves a good show: This week is a great week to go outside and do some skywatching. The Perseids, an annual meteor shower so named because it looks like they come out of the constellation Perseus, peak this week.
The Perseids are active from July 13th through August 26th, but they reach a spectacular crescendo during about a five-day window, centered on August 12th. Maximum activity is expected to occur on the morning of August 12th, when observers at dark-sky sites could see 200 meteors per hour.
In the early morning of the 12th, there’s a happy astronomical coincidence. The moon is in waxing gibbous phase, which is bright enough to interfere with your eyes adjusting to the darkness. But on the meteor shower’s peak, “the waxing gibbous moon will set between midnight and 0100 local daylight time as seen from mid-northern latitudes.” This means that the best, darkest hours of the night will be free of lunar illumination — all the better to see shooting stars with.
Better yet, the Perseids are known for producing fireballs: the long, glowing streaks as a piece of debris perhaps the size of a golf ball burns up during re-entry. “We have found that one meteor shower produces more fireballs than any other,” said Bill Cooke of NASA’s Meteoroid Environments Office (they apparently have one of those). “It’s the Perseid meteor shower, which peaks on August 12th and 13th.” And astronomers are excited: this time around, the light show could be double its usual intensity.
Every Perseid meteor is a piece of the comet Swift-Tuttle, which leaves a trail of debris in its wake. When the Earth plows through the comet’s orbital path, pieces of that debris get swept up into our atmosphere and then burn up. This year Jupiter’s gravity is pushing more of the huge network of dust trails into our own orbital path. Experts at NASA and elsewhere agree that three or more streams are on a collision course with Earth this year, and it’s bound to be a sensational experience.
If it’s cloudy, or if you’re in a place with light-polluted skies, you can watch the live webcast from NASA. But for the best, most direct experience, you should take a blanket and go find a place with dark skies. Bring some friends, and you can even bring Pokémon Go! to catch the ones you can only get at night — but don’t bring binoculars, because they’ll only limit your field of view. Remember that you’ll need to wait a while — up to an hour — for your eyes to adjust to the darkness, although thankfully the moon will be less of an obstacle this year.
Despite NASA’s advice to lie on one’s back and look straight up, the American Meteor Society says that the zenith is also the place where the atmosphere is thinnest, so you’ll have the worst chance of seeing a fireball if you look straight up. You’re better off centering your field of view at about 45 degrees, or halfway up in the sky — high enough to avoid anything that might block your view.
The bottom line? Wait until the wee hours of Friday or Saturday morning, and then go outside and look up!