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(meteorobs) Astrobioligists Flying High To Study Leonid Meteors

Nov. 15, 1999
Kathleen Burton
NASA Ames Research Center, Moffett Field, CA
(Phone: 650/604-1731, 650/604-9000)  kburton@mail.arc.nasadot gov

Laura Lewis
NASA Ames Research Center, Moffett Field, CA
(Phone:  650/604-2162, 650/604-9000)  llewis@mail.arc.nasadot gov

RELEASE:  99-71

NOTE TO EDITORS/NEWS DIRECTORS: You are invited to observe video footage of
the Leonid meteors from the mission on Wednesday, Nov. 17, from 2 p.m. to 6
p.m. (PT) in the main auditorium, N-201, at NASA Ames Research Center,
Moffett Field, CA.  To gain entry, show press credentials and photo ID at
the Visitor Badging Office, located at the Main Gate, Moffett Federal
Airfield.

ASTROBIOLOGISTS FLYING HIGH TO STUDY LEONID METEORS

To gain a better understanding of the way life may have evolved on Earth, a
team of scientists has begun a multinational airborne mission to study the
Leonid meteors.

The Astrobiology mission began when two U.S. Air Force planes, the ARIA and
the FISTA, lifted off from Edwards Air Force Base, Edwards, CA, on Nov. 13
at 11:15 a.m. (PT) enroute to Royal Air Force Mildenhall Airbase in the
United Kingdom.  During the mission, an international cadre of scientists
will point their instruments towards the sky to study the Leonid meteors
from the unique vantage-point of the aircraft.

"The planes provide a perfect platform for viewing the meteors," said Peter
Jenniskens, chief scientist for the Leonids mission. "They lift us above
the weather to ensure a fantastic view.  By flying over 35,000 feet in the
air, we are above most of the atmospheric water vapor, and our instruments
get the best data possible."

The Leonid meteor showers occur each November when the Earth passes through
the debris shed from periodic comet 55P/Temple-Tuttle.  The meteors, named
the Leonids because they appear to stream from the constellation Leo, are
about the size of a grain of sand.  Studying comets and meteors, which are
made from ice and dust that existed when the universe was formed, may help
scientists develop a better understanding of how life began on Earth.

"Comets and meteors are fascinating to study because they are a frozen
record from the time when the universe formed," explained astrobiologist
Dr. Scott Sandford of NASA's Ames Research Center, Moffett Field, CA.  "Due
to geological activity, all of Earth's materials have been reformed several
times over, and we must study comets, meteors and meteorites to get an
early view of our universe."

Most years, observers with ideal viewing conditions can see 10 to 20
meteors per hour during the Leonid showers.  Every 33 years when the parent
comet Temple-Tuttle passes particularly close to the Earth, as it did in
1998, meteor storms with hundreds or thousands of meteors per hour are
possible.  In 1998, following Temple-Tuttle's pass by Earth, counts of 250
meteors per hour were recorded.  Predictive models have indicated that, in
1999, it may be possible to see 200 to 5000 meteors per hour around the
longitudes of Europe and the Middle East.  The 1999 Leonid Multi-instrument
Airborne Campaign (MAC), a mission jointly funded by NASA and the United
States Air Force, has been designed to fly over these longitudes for three
consecutive observation nights, Nov. 16-18.

Both aircraft being used for the mission have been specially outfitted with
a variety of instruments, including spectrometers and cameras, to study the
meteors.  The FISTA, an NKC-135 aircraft, has been modified with 20
upward-facing viewing ports.  The ARIA, an EC-18 airplane, has telemetry
equipment that will allow researchers to send images and near real time
data regarding comet flux, or counts, to the ground.

Research objectives for the mission involve taking many measurements that
have never been done in airborne astronomy, including real-time meteor
counts, spectroscopy (mid-infrared, near-infrared, ultraviolet and visible)
and stereoscopic viewing of meteors using intensified high-definition
television cameras.  The stereoscopic view, obtained when instruments on
both aircraft image a meteor, will provide the first-ever three-dimensional
model of meteor trajectories.

About half of the scientists on the current mission participated in the
1998 Leonid MAC mission that flew over Japan.  That highly successful
mission is credited with observing more than 3,200 meteors, obtaining the
first differential spectrometry data from meteors as they burned through
the sky, and obtaining the first stereoscopic images of a persistent meteor
train.

After departing Edwards Air Force Base Nov. 13, the planes flew to
Mildenhall Airbase in the United Kingdom.  During the night-time crossing
of the Atlantic Ocean, scientists tested and calibrated their instruments
and completed initial observations, including taking measurements of the
Aurora Borealis.

The mission will begin Nov. 16 when the planes depart England and fly the
scientists overnight to Tel Aviv.  The following night, Nov. 17, during the
expected peak of the storm, the scientists will fly from Tel Aviv to Lajes
Air Base in the Azores.  The final night, Nov. 18, the planes will fly from
the Azores to Patrick Air Force Base in Florida.

The peak of the storm is expected to occur at 0200 (UT) Nov. 18 (9:00 p.m.
ET, Nov. 17) over Europe and the Middle East.  While the best viewing of
the storm will be in these locations, it may be possible to see the Leonid
meteors in the United States, particularly in the predawn hours of November
17 and 18.

For current information about the Leonid MAC Astrobiology mission, visit:
http://leonid.arc.nasadot gov/

-end-

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