There are several annual major displays of “shooting stars” that skywatchers look forward to with eager anticipation, and we have previewed them in this column a number of times over the years. Unfortuntely, at least one or more are typically spoiled by clouds, bright Moonlight flooding the sky, or peaking during daylight hours or on weekday nights when staying up late isn’t an option for those who must rise early for work. Except for the always unpredictable weather, one of the year’s best-known showers is ideally made to order this month.
On Saturday night, August 11th into the morning hours of Sunday, August 12th the annual Perseid Meteor Shower is predicted to put on quite a show. Perfectly timed over a weekend, observers can stay up late to follow the display into the morning hours if so inclined. Rising around 1:30 a.m. local time on the 12th, the waxing Moon itself will be heading towards its crescent phase and should be thin enough to offer minimal interference with visibility of the meteors. This display is expected to produce at least 60 “shooting stars” an hour at its maximum (that’s one-per-minute on average) and possibly as many as 100 an hour as seen from dark-sky locations.
The radiant — that point from which the meteors appear to “shoot” toward us — is located in the constellation Perseus (after which the shower is named). It will just be clearing the northeastern horizon around 9:00 p.m. local time on the 11th, and continue to climb ever-higher in the sky as the Earth spins in that direction. Use your Scientifics Star and Planet Locator to first identify it, and then see its altitude increase by setting the star-disk to later and later hours.
It’s also due to the Earth facing into the direction the meteors are coming at us that their numbers typically increase noticeably after midnight. But there’s always some uncertainty as to the actual time of peak activity, so it’s best to begin watching as soon as darkness falls on Saturday (perhaps going out every hour or so to check on activity).
Many avid meteor watchers like to do counts of the number seen in precise hourly intervals (technically known as determining “hourly rates”). This allows you to see if shower activity is increasing or decreasing. It can also provide valuable data if properly recorded for the various professional meteor societies around the world. In this country, you can contact the American Meteor Society at http://www.amsmeteors.org/ for much useful information about observing meteors in general and also submitting observations.
For optimum coverage of the Perseid shower, face east toward the radiant while at the same time concentrating your attention on the sky overhead — preferably reclining comfortably on a lawnchair or heavy blanket and pillow. And while this is basically a naked-eye activity since it’s important to canvass as large an area of sky as possible, using your Edmund binoculars is also encouraged for following the trails or “trains” often left behind by many of the brighter meteors. And for an added thrill, point them from time to time at the radiant itself — you may be lucky enough to see a few meteors coming directly at you, suddenly appearing from out of nowhere as brightening stars!
Former assistant editor at Sky & Telescope magazine & author of eight books on stargazing.