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Leonid MAC

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Kathleen Burton
NASA Ames Research Center, Moffett Field, CA
Phone: 650/604-1731, 650/604-9000
E-mail: kburton [at]

Laura Lewis
NASA Ames Research Center, Moffett Field, CA
Phone: 650/604-2162, 650/604-9000
E-mail: llewis [at]

RELEASE: 99-74

Nov. 16, 1999 -

Astrobiologists began their first airborne observation night to study the Leonid meteors on Nov. 16, as the Earth began to enter the debris train left by the periodic comet 55P/Tempel-Tuttle.

At 21:50 GMT, on Nov. 16, the ARIA and FISTA, two United States Air Force planes, departed from Mildenhall in the United Kingdom for Tel Aviv Israel. During the overnight flight to Israel, the two aircraft flew approximately 80-100 miles apart from each other and as high as 38,000 feet.

The mission flight path took the scientists southwest of Mildenhall, over Lands End and out of the United Kingdom. The aircraft then turned south to fly over north central Spain, and then turned east to fly over Barcelona. The flight continued over Corsica, across the boot of Italy, over central Greece, and across the Mediterranean into Israel. ARIA and FISTA landed in Tel Aviv at 04:20 GMT Nov. 17.

The scientists and crew members aboard the FISTA and ARIA had a very successful first night of their Astrobiology mission. In addition to observing meteors, the team took measurements of air glow, observed and recorded lightning over Spain, and saw Jupiter and Saturn clearly in the night sky. They also successfully demonstrated that live images of the meteors could be sent from the plane, over the TDRS satellite, to the Internet.

The science team on the FISTA was thrilled with the collected data. "By the end of this first mission night we have already exceeded the number of meteors we observed with our mid-infrared instruments during the entire 1998 mission over Japan," said Peter Jenniskens, Leonid mission chief scientist.

The mid-infrared spectrographs, contributed by the Aerospace Corporation, are being used to detect the unique fingerprint of complex organic matter - like that required for life - in meteors. The instruments are also expected to provide information on the formation of solid particles and the heat of the meteors as they enter the atmosphere.

"A total of 10 meteors crossed the field of view of our spectrograph," reported George Rossano, a researcher on the FISTA aircraft. "I'm hopeful that these meteors will result in the first successful mid-infrared fingerprint of a meteor."

On ARIA, the flux measurement team counted meteors without actually looking out the window to see them; researchers wore goggles that displayed images from cameras that were pointed out of the airplane's windows. The number of Leonid meteors and sporadic meteors counted by each team member was entered into a laptop computer.

Jane Houston, a member of the flux measurement team and one of several amateur astronomers on the mission, explained how the team differentiated between Leonid and sporadic meteors. "The Leonid meteors radiate from the constellation Leo, while sporadic meteors fall randomly across the sky."

Each of the team members' laptop computers was linked to a central laptop computer, and near real-time data indicating the total number of meteors counted was provided. "The methods developed to count meteors for this mission could revolutionize the way future meteor showers are monitored," claimed Kelly Beatty, another amateur astronomer on the flux measurement team.

At the end of the night, the flux team reported observing approximately 14 sporadic meteors per hour and a Leonid zenith hourly rate of approximately 15 meteors per hour. The zenith hourly rate is the number of meteors an observer on the ground would see under perfect observing conditions.

"These rates for Leonids are almost twice as high as those we would normally see the night before the expected peak," explained Dr. Jenneskins, "I'm optimistic this is an indication that we will see a good storm tomorrow night."

The peak of the Leonid storm is expected at 02:00 GMT Nov. 18 over Europe and the Middle East. The international science team studying the Leonids will be flying from Tel Aviv to Lajes Airbase during the storm peak. It may be possible to see the Leonid meteor storm in the United States on the night of Nov. 17 (9:00 p.m. EST). However, best viewing may actually be in the predawn hours of Nov. 18.

The Leonid Multi-instrument Airborne Campaign is an Astrobiology mission from NASA Ames Research Center at Moffett Field, CA. The campaign is jointly funded by the United States Air Force and the National Aeronautics and Space Administration. Astrobiology is an interdisciplinary field that studies the origin, evolution, distribution and destiny of life in the universe.

For current information about the Leonid Multi-instrument Airborne Campaign, and to watch live Leonid coverage on the Internet, visit:

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