November 16, 2012
Leonid Meteor Shower To Peak, Shine On Moonless Night This Weekend
John P. Millis, Ph.D. for redOrbit.com — Your Universe Online
For amateur sky watchers, this weekend promises quite the show. The annual Leonid meteor shower — which gets its name because the meteors appear to originate in the constellation Leo — is upon us, and this year should be pretty good.
The meteor shower will be visible during the latter half of the week, peaking early Saturday morning. Those in the Eastern part of the country should see the greatest rate — about two-dozen events per hour —between midnight and 3:00 am.
The viewing should be enhanced this year as a new moon means that the sky will be especially dark.
Comets and Meteors
Meteor showers are created when the Earth passes through a dust trail left behind by a comet on its way around the Sun. Essentially frozen chunks of ice and dust, comets are heated by the Sun and begin to evaporate, creating the beautiful tails for which comets are known.
As the Earth follows its orbit, it will occasionally, and predictably, pass through these dust trails and create the beautiful meteor showers that we see throughout the year.
The particles that make their way across the sky are usually only centimeters thick, but travel at enormous speed. As these meteors travel through the atmosphere they are heated by friction and glow hot as they are vaporized.
Larger meteors are possible and manifest themselves as fireballs, glowing longer and brighter than typical meteors and can sometimes survive long enough to reach the ground.
The Leonid Meteor Shower
Each year in the middle of November the Earth makes its way through the field of debris left behind by Tempel-Tuttle — a comet on a 33-year orbit around the Sun.
Early Saturday morning (late Friday night on the west coast) meteors will be seen lighting up the sky at a rate of about 25 per hour. While this is impressive, records indicate that in 1833 spectators were breath taken as more than 100,000 events per hour illuminated the sky.
Unfortunately, it will be some time before we catch another event of such magnitude. Tempel-Tuttle will not pass through Earth´s orbit to refresh the stockpile of meteoroids again for another two decades. And a close approach with Jupiter is expected to alter the comet´s path, so it may be even longer before we get a truly impressive meteor shower.