Astronomical Advisory: Perseid meteor shower arriving mid-August
PARI astronomers remind the public of the upcoming annual Perseid meteor shower, expected to peak this year August 12.
Meteors result from particles of dust causing the atmosphere to glow as the particles enter the upper atmosphere of the Earth. The Perseid meteors, or “Perseids,” are associated with Comet 109P/Swift-Tuttle. In 1866 Giovanni V. Schiaparelli, an Italian astronomer more widely known for discovering the “canals” on Mars, determined that the path of the particles resulting in the Perseids was identical with the orbit of Comet Swift-Tuttle which had been observed in 1862. This discovery was confirmation of a then innovative theory that meteor showers result from the debris of comets, a theory now widely accepted in astronomical circles. Since the Earth encounters this debris at the same point in space each time it makes its annual revolution around the Sun, we observe the Perseids close to the same date each year, around August 12.
At their peak Perseids are predicted to reach a display of about 90 meteors per hour around 3 p.m. EDT, on the afternoon of August 12. Of course, we won’t see any meteors during the daytime (although they can be detected with radio telescopes). However, the Perseid meteor shower is one of the more reliable showers and lasts for several days on either side of its peak so we can look for them for a few mornings before and after this date. The Perseids are best observed between about 11 p.m. and dawn from a clear, dark location with a good horizon. Look to the northeast to find the meteors appearing to radiate out of the constellation of Perseus the hero (just below the “W” of Cassiopeia). Binoculars or telescopes are not needed to observe meteor showers.
The good news is that, while the morning of August 12 should be best for observing Perseids this year, a few Perseids can be spotted before or after this date. The bad news is that there will be a waning gibbous moon that will rise around midnight each of these nights; thus, moonlight will interfere with observations of the fainter Perseids this year.