For millions of Europeans and North Americans, this year's Leonid meteor shower will provide a not-to-be-missed treat. But those brief flashes of incandescence also reveal telltale clues about the Leonids' parent comet, 55P/Tempel-Tuttle, and how meteoric dust interacts with our atmosphere. So the pressure is on to maximize the Leonids' scientific potential, and when this year's display reaches its crescendo, scores of researchers around the world will likely be concentrating too hard on their experiments to enjoy the show overhead.
European astronomers are well positioned to study the first of November 19th's two predicted outbursts, which should peak near 4:00 Universal Time. A team from the European Space Agency is readying equipment on Pico Veleta near Granada in southern Spain. Led by Detlef Koschny, the researchers will use ultrasensitive video cameras to record detailed light curves of meteor flashes. To aid the ESA effort, the nearby 30-meter IRAM radio telescope will monitor the Leonid shower's intensity using echoes of radio transmissions mirrored by ionized gas along the meteors' paths.
Meanwhile, across the Mediterranean, Noah Brosch (Wise Observatory) had planned to outfit the cockpit of a commercial Boeing 757 aircraft with a pair of intensified video cameras, then have the plane crisscross the Mediterranean between Israel and Crete several times over five hours. To help defray the cost of the chartered jet, the flight was to carry some 200 paying passengers. Unfortunatley, Brosch reports, not enough tickets were sold, and the flight has been canceled. Instead, his team will observe from the ground, even though the storm's first maximum won't be observable from Israel due to twilight. Brosch also expects to collect radar-echo data, which will help pinpoint the meteors' altitudes.
The most concentrated scientific effort, by far, will be the Leonid Multi-instrument Aircraft Campaign, coordinated by Peter Jenniskens (NASA/Ames Research Center). This year's effort pairs NASA's DC-8 research aircraft with the U.S. Air Force's Flying Infrared Signature Technology Aircraft (FISTA), a heavily instrument KC-135 cargo craft. Flying in tandem westward over the Atlantic Ocean, the two planes will observe the cascade of meteors in stereo using sensitive cameras, spectrometers, and specially trained amateur astronomers who will record the meteors' arrival rates and magnitudes.
Jenniskens, who hopes to find the spectral signature of organic compounds in the flash spectra, has conducted similar airborne efforts during four of the past five years. "We are looking for clues about the diversity of comets and their impact on the chemistry of life's origin on Earth," he explains. Results from the Leonid MAC mission can be viewed in near-real time on the "Leonids Live" web site.
Another major scientific effort is taking shape at Kirtland Air Force Base, not far from Albuquerque, New Mexico. Jack D. Drummond and a dozen colleagues from the Starfire Optical Range (SOR) hope to glean everything they can from the glowing trains that can linger in the upper stratosphere for up to an hour after the passage of a Leonid fireball. This time, in addition to a phalanx of camera and video equipment, the SOR's 3.5-meter telescope will be paired with a high-resolution, high-sensitivity spectrophotometer on loan from Sandia National Laboratories. Observers from the Albuquerque Astronomical Society will help establish the altitudes at which the trains form. "We intend to answer once and for all what creates the light in those trains," Drummond vows.