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Public to Help NASA, SETI Institute, Other Scientists Study Meteor Shower
08.13.07
 
When Comet Kiess' dust trail briefly encounters Earth in the dark, early morning hours of Sept. 1, 2007, astronomers predict that an extremely rare Aurigid meteor shower will result. Meteor showers happen when comet dust streaks into Earth's atmosphere and vaporizes.

To help document the uncommon event, researchers hope the public will submit digital photos and camcorder movies of the shower's "shooting stars" to a team of scientists from NASA and other organizations.

The cause of the Aurigid meteor showers is very old. About 2,000 years ago, comet Kiess passed the sun and ejected a cloud of dust. The comet completed its first orbit of the sun in 1911 when Lick Observatory's Carl Kiess discovered the object. Its dust formed a continuous stream of particles that has been flowing just outside Earth's orbit ever since.

On Sept. 1, 2007, the Earth will travel through the stream of dust particles in the wake of the 1911 return of comet Kiess, according to astronomer Peter Jenniskens, an expert on meteor showers, who works for the SETI Institute, Mountain View, Calif. "Meteors will radiate from the constellation of Auriga, many as bright as the brighter stars in the sky," said Jenniskens, who also works at NASA Ames Research Center, Moffett Field, Calif.

According to Jenniskens, the shower will be visible by the naked eye from the western United States, especially in California, Hawaii, Alaska and other western states and Mexico and the western provinces of Canada. Prime viewing time will be on Saturday, Sept. 1, 2007, from 4:06 a.m. – 5:06 a.m. PDT, Jenniskens forecasts. Astronomers believe the whole event will last no longer than one-and-a-half hours and will not be seen again in our lifetimes.

Sunlight has pushed the comet's ejected particles into wider orbits around the sun in a thin stream just outside of Earth's orbit. "On occasion, the combined gravity of the solar system's planets moves this dust trail into Earth's path," Jenniskens, explained.

Jenniskens and fellow researchers Jérémie Vaubaillon of the California Institute of Technology, Pasadena, Calif., and Esko Lyytinen of Finland, predicted the upcoming, rare Aurigid shower.

According to Jenniskens, as dust grains from comet Kiess collide with Earth's atmosphere during the Aurigids shower, they will begin to vaporize at about 80 miles altitude, and the bigger comet particles will penetrate as low as 50 miles.

Jenniskens is leading a team of scientists and astronomers to study the Aurigid meteor shower from two aircraft. The airplanes will take off late Friday night, Aug. 31, 2007, from Moffett Field at NASA Ames, and will carry researchers from NASA, the SETI Institute, Utah State University and other organizations to a location high above the Pacific Ocean to view the meteor shower early Saturday morning, Sept. 1.

The primary goal of the mission is to count the meteors over the large area visible from the airplanes and measure the exact duration and peak time of the shower. Scientists will observe how the meteors break up and examine their colors to learn about the materials that formed the solar system.

Not only is the shower rarely seen, the Aurigid meteors also may be very unusual, Jenniskens noted. They are solid bits of the icy comet Kiess that returned from the Oort cloud of comets on the outskirts of the solar system.

"Billions of comets have spent 4.5 billion years in the Oort cloud, where cosmic rays baked their crust over the age of the solar system," Jenniskens said. "Some of the Aurigid meteors could be bits and pieces of this original crust of the comet. Comets that return more frequently to the sun have long lost this pristine crust," he observed.

Tips for setting up a digital camera or camcorder to take images of meteors

Meteors, or "shooting stars," look like streaks of light, or sparks flying from a distant campfire or fireworks. Observers can photograph meteor streaks by pointing digital cameras and camcorders towards the sky, but away from the moon.

The Aurigid meteors ("shooting stars") will look as if they are coming from the constellation Auriga (Latin for charioteer) in the northeastern sky. Perseid meteors will seem to originate from the constellation Perseus, just above Auriga. Astronomers named the showers for the constellation of stars from which the meteors appear to be derived.

Astronomers suggest that photographers go to safe locations that are far away from the haze of cities. According to astronomers, dust in the atmosphere in metropolitan areas will scatter moonlight and make the sky too bright to photograph or see the meteors well.

Jenniskens suggests that people who wish to contribute digital images to scientists should first use their cameras' "clock set" options to set them to the correct time, accurate to within one second. To find out the correct time, photographers can dial time-of-day services provided by telephone companies in their local areas. For example, in the San Francisco Bay Area, photographers can dial the letters on their telephones that spell "popcorn" (415-767-2676).

Photographers should place their cameras on tripods and use a "night," "bulb" or similar camera setting, so the volunteer observers can shoot meteor pictures with exposure times of 10 seconds, one after the other. Photographers should set the camera's light sensitivity to ISO 1600, according to Jenniskens.

"Choose a fairly small field of view that is no larger than the square of (the constellation) Pegasus," he said. "Take many successive 10-second-duration exposures," he added.

According to Jenniskens, volunteers should not move their cameras once they are set to take images, so that the frequency rate of the meteors can be measured. After the shower, each volunteer should record his/her observing location on a map, look at each of their images and make a list with the time each meteor picture was taken, Jenniskens said.

"Do not alter the digital images because scientists will use photo-editing programs to analyze the different colors in the images to learn about the meteors' compositions," Jenniskens advised.

According to Jenniskens, people interested in videotaping the meteors also should first set their camcorder clocks to the correct time. "Set the camera so that the time is recorded on the video picture (date not needed)," Jenniskens said.

"Mount the camcorder on a tripod, and then point to a region in the sky with many bright stars. Zoom in enough to see those bright stars in the video. Continue videotaping for the duration of the shower. Do not move the camera during the shower. Later, watch the video to find the meteors and provide a list of times, and record your location on a map," he noted.

Those people who would like to contribute their images and other observations to researchers should send them by e-mail to pjenniskens@seti.org.

The public may also upload their images and data to the Aurigid Meteor Shower Web site at:

http://aurigid.seti.org

According to Jenniskens, other organizations interested in obtaining meteor images and observations from volunteers include the American Meteor Society and the International Meteor Organization.

To view images, from a meteor shower that occurred on Aug. 13, visit:

http://www.nasa.gov/centers/ames/multimedia/images/2007/Aurigid.html

To view a vodcast about the Aurigid meteor shower, visit:

http://www.nasa.gov/centers/ames/multimedia/podcasting/Aurigids.html

To view images of unexpected Kappa Cygnids meteors on Aug. 13, visit:

http://www.nasa.gov/centers/ames/multimedia/images/2007/Kappa_Cygnids.html

To view a vodcast about the Kappa Cygnids meteors on Aug. 13, visit:

http://www.nasa.gov/centers/ames/multimedia/podcasting/Perseid.html

To view images from past meteor observation campaigns, visit:

http://leonid.arc.nasa.gov

 
 
John Bluck
NASA Ames Research Center, Moffett Field, Calif.
Phone: 650-604-5026
Email: jbluck@mail.arc.nasa.gov