Will it be an astounding meteor storm -- 1,000 shooting stars per hour -- or a breathtaking meteor shower, 100 zenith hourly rate (ZHR)? Will we thrill to slow-moving fireballs or find a placid sky?
Leading scientists are predicting a new meteor shower overnight Friday, peaking Saturday between 2 a.m. and 4 a.m. Earth will travel through the debris stream of a comet named 209P/LINEAR, discovered in 2004 by an automated sky survey of the Lincoln Near Earth Asteroid Research project.
A meteor shower occurs when Earth passes through rubble trails left by a comet. Comets are icy, rocky celestial bodies described as dirty snowballs. Some visit the inner solar system from far beyond Pluto, never to return. Others, like Swift-Tuttle -- the parent of August's Perseid meteor shower -- return periodically. Swift-Tuttle has a 133 year cycle of orbiting from the outer solar system's Kuiper Belt for a swing around our sun and back. The recently discovered comet LINEAR is characterized as a tiny periodic comet that has a mere 5.04 year cycle, its farthest point from the sun being near Jupiter's orbit.
Although 209P was unknown to observers until 10 years ago, researchers discovered that its rubble trails from 1803 to 1924 will intersect Earth's orbit Friday through Sat urday, the same time the comet itself will be near. LINEAR, however, will not be visible to the naked eye.
NASA suggests watching in dark sky areas away from city lights from late night Friday until pre-dawn Saturday, given that there are many unknowns. Scan generally and especially toward the North Star, above the Big Dipper.
To contact Judy Isacoff go to www.naturesturn.org