Perseid meteor shower, an annual display of shooting stars in Northern Hemisphere, is nearing its peak time of 2011.
Perseid shower, caused by debris from Comet Swift-Tuttle and observed for 2000 years, normally peaks at 100 or more meteors per hour in the absence of moonlight on new moon.
This year, unfortunately, when the shower peaks this Friday generating 60 or more meteors per hour, the majestic view will be hampered by the full moon, which will wash out all but the brightest meteors. The meteor will be visible only at 20-30 per hour at most at the peak overnight on August 12 and 13.
Tonight, however, may be the time when the Perseids are most visible to the naked eye.
Just before the dawn very late tonight or early Wednesday morning, the Perseids could give the best view, according to Earth Sky. If blessed with clear skies, the predawn hour will be the rare window of opportunity of dark, moonless skies. The predawn time on August 10 and 11 will also be good opportunities to watch the shower.
The Perseids are typically fast, bright and occasionally leave lingering trains. A Perseid fireball would sporadically blaze up brightly to add to the spectacles in the night sky.
A meteor shower is a celestial event in which a number of meteors are seen radiating the night sky. Most meteors are smaller than a grain of sand, and almost all of them disintegrate and never hit Earth's surface.
Intense or unusual meteor showers are known as meteor outbursts and meteor storms, which may produce greater than 1,000 meteors an hour, according to a Cambridge University research study.
Meteor showers occur as the result of a passing comet. As the comet approaches and rounds the Sun, it sublimates (turns from a solid directly into a gas, like dry ice), creating a cloudy sphere, called the coma, around the nucleus. The solar wind pushes on the coma forming the long comet's tail, which always points away from the Sun.
Although the comet is nowhere near Earth, its tail does intersect Earth's orbit. Tiny bits of comet dust that hit Earth's atmosphere travel 140,000 miles per hour.
Because of the speed, even a smidgen of dust makes a vivid streak of light--a meteor--when it disintegrates. As Swift-Tuttle's meteors fly out of the constellation Perseus, they are called Perseids.
Some Catholics refer to the Perseids as the "tears of St. Lawrence", since August 10 is the date of that saint's martyrdom. In 2009, the estimated peak Zenithal Hourly Rate was 173, but fainter meteors were washed out by a waning gibbous moon.