The spectacular Geminid Meteor shower hits peak activity this weekend. Though competing with some unfortunate moonlight, the shower still should make for a must-see astronomical event.
While moonlight will somewhat hinder this year’s Geminid meteor shower, intrepid observers with good weather and low light pollution should still be able to catch a good meteor show Saturday (Dec. 13) night.
“If you have not seen a mighty Geminid fireball arcing gracefully across an expanse of sky, then you have not seen a meteor,” note astronomers David Levy and Stephen Edberg.
Even if you can’t see the meteor display from your part of the world, you can watch them . The online Slooh Community Observatory will host a live webacst of the Geminid meteor display on Saturday night beginning at 8 p.m. EST (0100 Dec. 14 GMT).You can also watch the Slooh webcast directly:http://live.slooh.com/. NASA meteor expert Bill Cooke will also host a live Geminids webchat on Saturday night from 11 p.m. to 3 a.m. EST (0400 to 0800 GMT), as well as a live webcast.
You can watch the webcasts of the Geminid shower live on Space.com, starting at 8 p.m. EST, courtesy of Slooh and NASA. The Italy-based Virtual Telescope Project will also host a Geminds webcast, beginning at 9 p.m. EST (0200 GMT).
Although the bright moon will be high in the sky by 11:30 p.m. local time Saturday (Dec. 13) (during the shower’s peak), skywatchers can still catch a potentially incredible show before the moon creeps above the horizon, washing out the sky. Stargazers might be able to see an average of one or two Geminid meteors per minute Saturday before the moon rises.
By around 9 p.m., the constellation Gemini — the part of the sky where the meteors seem to emanate from — will have climbed more than one-third of the way up from the horizon. Meteor sightings should begin to really increase noticeably thereafter. By around 2 a.m., the last-quarter moon will be low in the east-southeast, but Gemini will stand high overhead. So you might still see a good number of meteors in spite of the moon’s presence.
A brilliant shower
The Geminids are, for those willing to brave the chill of a December night, a very fine winter shower, and usually the most satisfying of all the annual showers. They can even surpass the brilliant August Perseid meteor shower.
Studies of past displays show that the Geminid shower is rich both in slow, bright, graceful meteors and fireballs, as well as in faint meteors, with relatively fewer objects of medium brightness. Many Geminids appear yellowish in hue; some even appear to form jagged or divided paths.
These meteors at a medium speed and appear to emanate, specifically, from near the bright star Castor, in the constellation of Gemini, the Twins, hence the name “Geminid.” In apparent size, that’s less than half the width of the moon. As such, this is a rather sharply defined radiant as most meteor showers go. It suggests the stream is “young,” perhaps only several thousand years old.
Generally speaking, your location, Castor begins to come up above the east-northeast horizon right around the time evening twilight comes to an end. As the Gemini constellation begins to climb the eastern sky just after darkness falls, there is a fair chance of perhaps catching sight of some “Earth-grazing” meteors. Earthgrazers are long, bright shooting stars that streak overhead from a point near to even just below the horizon. Such meteors are so distinctive because they follow long paths nearly parallel to the Earth’s atmosphere.
Because Geminid meteoroids are several times denser than the comet dust that supply most meteor showers and because of the relatively slow speed with which the Geminids encounter Earth (22 miles or 35 kilometers per second), these meteors appear to linger a bit longer in view than most. As compared to an Orionid or Leonid meteor that can whiz across your line of sight in less than a second, a Geminid meteor moves only about half as fast. Personally, their movement reminds me of field mice scooting from one part of the sky to another.