The Perseids are a very strong meteor shower that occur during the months of July and August. It has documented viewings going back for almost 2,000 years with early documentation coming from observers in the Far East and has long been recognized as one of the most prolific meteor showers of the year.
The source of the Perseids meteor shower is the comet Swift-Tuttle. Swift-Tuttle is an extremely large comet, approximately the size of the asteroid that is credited with the extinction of dinosaurs some 65 million years ago, making the tail of the comet immense as well. Each year as the Earth moves through the comet tail, we are gifted with a strong astronomical event that thrills both astronomers and amateur observers alike.
In any given year the Perseids meteor shower has an average zenithal hourly rate (ZHR) of 40-60 meteorites per hour during it’s peak dates. The Perseids shower starts on July 17th and ends around August 24th, with the greatest amount of activity for the shower between the 8th and 14th of August, and a peak date around August 12th. In some years the Perseids have proven to be even more prolific during their peak period, providing observers with 100-200 streaks per hour.
In recent years there has been a slight increase in the number of meteorites that are able to be observed from the Perseids shower. Astronomers have discovered that this comes from a filament cloud from the comet which was burned off sometime during the mid 1860’s. This particular filament cloud is more condensed than the rest of the filament cloud that resides in the Perseid cloud, which helps to make the stream more meteorite dense, and provides us with a stronger meteor shower. Eventually however, this filament will disperse as well and the number of meteorites viewed will drop slightly, though the Perseid shower will still remain strong.
When viewing the Perseids meteor shower, seek out the constellation of Perseus in the night sky. This is the radiant of the shower and the location which the meteorites appear to originate. Though meteorites from the Perseids can be seen across the entire sky, they are most visible in the northern hemisphere since the constellation of Perseus is not as visible if you are located south of the Earth’s equator.
In order to get the best view of the Perseid meteor shower, plan on viewing the shower during it’s peak times from August 11th to August 13th. The shower is best viewed in the hours before dawn, so the best viewing time is around 2 am in the morning. During this time you will be able to see between 40-60 meteorites per hour, if not more, which will be brightly streaking across the sky creating an astronomical light-show that you won’t soon forget.
Christopher L. Shelby, M.D.