Every year in August, Earth passes through a stream of debris from Comet Swift-Tuttle, source of the annual Perseid meteor shower. The shower is beloved by sky watchers. It is rich in fireballs and plays out over a two-week period of warm, starry summer nights.
This year’s display is going to be even better than usual. “Our models predict an outburst on Aug. 11-12 with peak rates greater than 200 meteors/hour under ideally dark skies,” explains Bill Cooke of NASA’s Meteoroid Environment Office. “That’s about twice as many Perseids as usual.”
Perseids in Aug. 2015, a composite image by Petr Horalek of Kolonica, Slovakia [more]
In ordinary years, Earth grazes the edge of Swift-Tuttle’s debris zone. Occasionally, though, Jupiter’s gravity tugs the huge network of dust trails closer, and Earth plows through closer to the middle. This appears to be one of those years. Experts at NASA and elsewhere agree that three or more streams are on a collision course with Earth–hence the outburst.
Observing tips: Go outside between midnight and dawn on the morning of Aug. 12th. Allow about 45 minutes for your eyes to adjust to the dark. Lie on your back and look straight up. Perseids can appear anywhere in the sky, but their tails will point back to a single point in the constellation Perseus: sky map. Increased activity may also be seen on the morning of Aug. 13th.
Got clouds? NASA is planning a live broadcast of the Perseid meteor shower overnight on Aug. 11-12 and Aug. 12-13, beginning at 10 p.m. EDT. You can also listen to radar echoes from the Perseids on Space Weather Radio. More webcasts: from Israel, from Alabama.