The annual Perseid meteor shower has already begun and it will peak later this week with the best viewing set for midnight-to-dawn early Friday morning (August 12) and midnight-to-dawn early Saturday morning (August 13). The Perseid meteor shower comes every August as the Earth passes through a cloud of dust that comes from Comet Swift-Tuttle as it approaches the sun. Earth's gravity pulls in some of the chunks of debris — small rocks comprised of iron-nickel, stone, other minerals or a combination of these — which turn into bright balls of hot gas when entering Earth's atmosphere. In dark locations with clear skies, the Perseid meteor rate usually averages from 60 to 100 per hour, but this year could be as high as 200 in an hour - of course that is all weather permitting.
Perseid meteoroids hit our atmosphere at ~132,000 mph to produce the annual light show and this particular meteor shower is usually rich in “fireballs” because of the size of the parent comet. Comet Swift-Tuttle has a huge nucleus – about 26 kilometers in diameter whereas most other comets are much smaller with nuclei only a few kilometers across. As a result, Comet Swift-Tuttle produces a large number of meteoroids, many of which are large enough to produce fireballs. In fact, the Perseid meteor shower is considered the “fireball champion” of all of the annual meteor showers.
As darkness falls, the meteors appear to come from the constellation Perseus, hence the name; although late in the evening, the meteors originate higher in the sky than the constellation. The best time to look during the peak is between the hours of midnight and dawn far away from city lights. Typically, the meteors are only the size of pebbles, some as small as a grain of sand. This should be an especially good year for viewing dependent on the weather - and it is looking somewhat iffy - as the Earth will collide with more material than usual since it will move closer to the middle of the stream, rather than at the edge. In fact, Earth may collide with three or more streams during the shower this year. This could result in double the usual rate of meteors, and a spectacular rate of 200 meteors per hour under perfect conditions.
Meteorologist Paul Dorian