Above: A bright Perseid meteor streaks past Orion's Sword (note the pinkish Orion Nebula just right of center) early on the morning of August 12, 1997. Astrophotographer Wally Pacholka of Long Beach, California, captured this view on Fuji 800 film through a 50-mm f/1.7 lens. He observed the shower from Joshua Tree National Park and shot this photo around 5 a.m. Click on the image to pull up a larger version (46K JPEG). © 1997 Wally Pacholka.
Spectacular Meteor Showers Possible This Autumn! Click Here for Details!
At one time or another, almost everyone has glimpsed a swift little streak of light dashing across the night sky. These sudden celestial visitors are meteors, commonly called falling or shooting stars. Meteors are pieces of space debris that plow into the Earth's atmosphere. Because they arrive at very high speeds -- anywhere from 4 to 28 kilometers (2½ to 17½ miles) per second -- they vaporize by air friction in a white-hot streak. Most meteor parents (meteoroids) range in size from sand grains to pebbles. Occasionally a larger object will survive its descent and fall to Earth -- then it's called a meteorite.
A meteor that appears brighter than any of the stars and planets is called a fireball. A spectacular fireball is often reported over a distance of 200 miles or more. The sudden appearance and fast motion of a bright meteor produces an illusion of closeness that can fool even well-trained professionals. Airline pilots have swerved to avoid meteors that were actually 100 miles away.
Most meteors are seen 50 to 75 miles above the ground. Occasionally someone will claim to see a fireball land just beyond a tree or a hilltop, but in fact a typical fireball first appears at a height of about 80 miles and loses its brightness while still at least 12 miles above the ground.
Much more abundant are smaller, everyday meteors. While most look white, some appear blue, green, yellow, orange, or red. One that explodes at the end of its visible flight is called a bolide. At certain times of the year we see more meteors than usual. This happens when Earth passes near a comet's orbit and sweeps through debris that the comet has shed. Such events are called meteor showers. For the major annual meteor showers, seeing one meteor every few minutes is typical, though there are often bursts and lulls.
Shower meteors can appear anywhere in the sky, but their direction of motion is away from the constellation whose name the shower bears. This apparent point of origin is known as the radiant. Some observers feel that the best place to watch is between a shower's radiant and the zenith (the point directly overhead). In general, you'll do best by watching the darkest part of your sky, wherever you may be.
All you need to observe these celestial displays are a dark sky, a way to stay comfortable, and a little patience. Light pollution or moonlight will drastically reduce the number of meteors you see, so plan accordingly. Give your eyes at least 15 minutes to adjust to the dark. Make yourself comfortable with a reclining lawn chair, sleeping bag, snacks, music, the company of other stargazers, or whatever will help you remain interested enough to keep your eyes turned toward the sky.
Here are some of the best of the year's meteor showers. Look for further information in future issues of Sky & Telescope or right here on the magazine's Web site.
Leonids (Nov. 17-18). The Leonid shower occurs when Earth passes near the orbit of Comet 55P/Tempel-Tuttle. When the comet visits the inner solar system, the Leonid shower sometimes produces a veritable storm of meteors. This last occurred in 1966, when up to 40 meteors per second were seen for about an hour! Both 1998 and 1999 are good years to watch for a possible repeat of this performance. Best chances: the early morning hours of November 17 or 18, 1998, and November 18, 1999.
Geminids (Dec. 12-14). This is the only major meteor shower known to be associated with an asteroid (3200 Phaethon). It should peak on the night of December 13-14, 1998, and the nights of December 13-14 and 14-15, 1999. An observer may see 80 meteors in an hour under moonless, rural skies from late evening through dawn. A suburban observer may see only 30 meteors or fewer per hour. The prime observing hours are essentially Moon-free in both 1998 and 1999.
Perseids (Aug. 8-15). This best-known meteor shower has a broad peak, and it occurs at a pleasant time of the year for Northern Hemisphere observers. With the Moon near new and out of the sky all night, 1999 should be a great year for the Perseids. In recent years there have been two peaks about a half day apart. The morning of August 13, 1999, should be the best time to watch, but rates should remain high for a day or two on either side. A single observer may see 50 to 100 meteors per hour under dark, rural skies in the hours before dawn. Rates in the evening are much lower. Suburbanites may expect closer to 25 to 40 meteors per hour even during the peak predawn hours. Brief outbursts sometimes enhance these rates greatly.
For more information, please choose one of the following. Or see below for selected links to other meteor-related Web pages.
- Return of the Leonid Meteors
- The Leonids: King of the Meteor Showers
- Leonids 1833: The Night of Raining Fire
Here are some links to other meteor-related resources on the World Wide Web:
- International Meteor Organization
- A global clearinghouse; the place to share your meteor-shower observations with other interested amateur astronomers.
- North American Meteor Network
- This recently formed group trains meteor watchers in the U.S., Canada, and Mexico and helps to coordinate their observations.
- Gary Kronk's Meteor Showers Page
- Many useful resources from an amateur astronomer who specializes in comet and meteor observations. This site hosts the NAMN pages too.
- American Meteor Society
- Based at the State University of New York, College at Geneseo. Promotes the observation and study of meteors.
- Dutch Meteor Society
- Known worldwide for their careful photographic studies of meteors, this group regularly publishes its results in professional journals.
- Sino-Dutch Leonid Expedition 1998
- Members of the Dutch Meteor Society (see previous link) are planning to travel to China to maximize their chances of witnessing a Leonid meteor storm. Travel with them via the Web!
- Leonids Live!
- Watch the Leonid meteor shower live from Japan, where prospects for a meteor storm are excellent on November 17-18, 1998.
- Russ Kempdon's Meteorite Page
- Everything you ever wanted to know about meteorites, in a well-organized, well-illustrated format.
- NASA-Ames Research Center
- Information concerning past and future apparitions of the Leonid shower, which may produce an impressive meteor storm in 1998 or 1999.
- Jordanian Astronomical Society
- Members of this organization have begun observing meteors by radio. Learn how you can do the same.
The editors of Sky & Telescope are always eager to receive copies of observing reports and images of meteor showers. You can send them by e-mail to S&T's Observer's Log or by surface mail to the address at the bottom of this page.
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