Meteors will light the winter sky
The Quadrantids, one of the best but least-known meteor showers, will shine in the new year.
December 28, 2007
The annual Quadrantid meteor shower is one of the year's best. In 2008, this shower will be especially good because it's at its best under a nearly New Moon. So, not only will you see bright meteors easily, you'll also count quite a few fainter "shooting stars."
The Quadrantid meteor shower peaks before dawn January 4. There will be little interference from the waning crescent Moon, so observers with clear skies should see a great display.
Photo by Astronomy: Roen Kelly
The Quadrantids peak between 1 A.M. and dawn January 4. This is the best time to see the meteors. New Moon occurs January 8, so when the thin crescent Moon rises around 5 A.M. on the 4th, its light won't create much of a distraction.
You'll need a clear, dark sky to see more than just a few Quadrantids. "Dark" means at least 40 miles from the lights of a large city. You won't need a telescope or even binoculars — in fact, the eyes alone work best because they provide the largest field of view.
Comfort counts when observing meteor showers. Most importantly, you must keep warm. Observing is not a physical activity — you'll just be standing or sitting. When you're ready to start observing, set up a lawn chair, preferably one that reclines. To see the maximum number of meteors, just look overhead. Glancing around won't hurt anything.
Astronomy magazine contributing editor Raymond Shubinski, who has observed more than 100 meteor showers, advises observers to keep a running tally of meteors. "By doing that, you'll get a good idea of how your site compares with observing sites around the world."
How many Quadrantids will you see? Most years under clear, moonless conditions, observers count 120 meteors per hour from a dark site. That's an average of two shooting stars a minute!
The Quadrantids were given that name because, if you trace all the meteor trails backward, they meet within the boundaries of the now-extinct constellation Quadrans Muralis the Mural Quadrant. This constellation originally sat between the right foot of Hercules, the left hand of Boötes, and Draco. It represented the mural quadrant of French astronomer Jérome Lalande (1732–1807). Lalande used his quadrant to chart some 50,000 stars while at the College de France. French globe-maker J. Fortin introduced Quadrans Muralis as a constellation in his atlas of 1795.
The Quadrantid meteor shower originated from a near-Earth asteroid named 2003 EH. Although astronomers classify 2003 EH as an asteroid, most believe it to be a dead comet. Observers first recognized the Quadrantids as an annual meteor shower in 1839.
|Meteor shower facts|
Meteors are small particles of rock and metal Earth encounters (runs into) during its orbit around the Sun. In space, these particles are called meteoroids. When they burn up in the atmosphere, they are called meteors. If they survive the fiery ordeal of passage through our thick blanket of air and land on Earth, they are then known as meteorites. No meteorites are generated from meteor showers — the particles are too small.
All meteor showers except December's Geminids and January's Quadrantids originate from comets. When a comet swings around the Sun, it leaves a trail of debris (small meteoroids). Sometimes, the orbit of this debris crosses Earth's orbit. When Earth runs into this stream of particles, we experience a meteor shower.
No known meteorite has come from a meteor shower. (That is, no shower meteor has ever survived its flight through the atmosphere and been recovered.)
|Interesting facts about meteors|
To be visible, a meteor must be within about 120 miles (200 kilometers) of an observer.
Meteors become visible at an average height of 55 miles (90 km). Nearly all burn up before they reach an altitude of 50 miles (80 km).
The typical bright meteor is produced by a particle with a mass less than 1 gram with a size no larger than a pea.
The hourly rate on a "non-shower" night is approximately 6 meteors per hour.
A meteoroid enters the atmosphere at velocities between 50,000 and 165,000 mph (81,000 and 265,000 km/h).