PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011

Contact: Stephanie R. Zeluck

March 31, 1997


      Astronomers Dr. Alan Hale, Thomas Bopp, David Levy and Dr. Don Yeomans will participate in a Comet Hale-Bopp viewing event and panel discussion about comet exploration titled "Comet Chasers: On the Trail of a Comet," at the California Institute of Technology's Beckman Auditorium on Friday, April 11.

      Admission to the public event is free, but tickets are required to attend. Tickets are available from the Caltech Ticket Office, 332 S. Michigan Avenue, Pasadena; by phone at (818)395-4652; via fax at (818)795-1378; or via the Internet at There is a limit of four tickets per request. For those outside Southern California, the panel discussion will also be broadcast via Internet.

      The event will present an opportunity for the public to view Comet Hale-Bopp and Comet Wild-2 (pronounced "vilt two") through telescopes provided by the Jet Propulsion Laboratory's Astronomy Club.

      Following the comet viewing, an hour-long panel discussion introduced by JPL Director Dr. Edward Stone and moderated by Levy will take place in Caltech's Beckman Auditorium. Astronomers Hale, Bopp, Yeomans and Levy will comprise the panel, discussing comets Hale-Bopp and Wild-2, and NASA's future spacecraft designed to fly past the rare celestial visitors.

      Comet Hale-Bopp was discovered independently on July 22, 1995, by astronomer Hale and amateur astronomer Bopp from outside their respective locations of Cloudcroft, NM, and Phoenix, AZ. At the time of its discovery, Comet Hale-Bopp was more than 929 million kilometers (577 million miles) from Earth, appearing over 1,000 times brighter than Comet Halley did at that same distance.

      Recently, Comet Hale-Bopp has been visible in the northeast sky in the early morning before dawn, and in the northwest sky just after evening twilight. In the coming days, the comet will no longer be visible in the early morning hours. At the time of the "Comet Chasers" event, Hale-Bopp will appear quite bright and about 25 degrees up from the horizon in the northwest sky just after sunset. This will be the highest point at which the comet will appear, and it will set in the west after about two hours.

      Levy, the panel discussion's moderator, is an amateur astronomer who discovered Comet Shoemaker-Levy 9 in March 1993 along with Dr. Eugene and Carolyn Shoemaker using a 1.2-meter (48-inch) Schmidt telescope on Mount Palomar in California. That comet went on to impact Jupiter in July 1994, providing the first Earth- and space-based observation opportunities for viewing a planetary collision by a comet.

      "Comet Hale-Bopp is living up to its advanced billing" said Yeomans, supervisor of JPL's Solar Systems Dynamics Group. "It's the brightest comet in 20 years, and can be easily seen by inexperienced observers. The only comparable comet was Comet West seen in March 1976, which at its best was slightly brighter than Hale-Bopp is now, but I'm hopeful that this comet will become as bright as Comet West. It's rare that you get one that's so civilized -- showing up in the evening sky about an hour after sunset in the middle of prime time."

      Comets, composed of ice and dust, are believed to be remnants of the birth of the solar system. Their primordial material may lend clues in learning more about the origin and evolution of the planets. Originating in a region from beyond the orbit of Pluto, comets can have orbits taking several thousand years to complete. Hale-Bopp last passed by Earth 4,200 years ago, and is not expected to return for another 2,400 years.

      Panelists will discuss several ambitious NASA missions that will further study the nature of comets in order to learn more about the evolution of the solar system. Stardust, scheduled for launch in 1999, will capture material thrown off by Comet Wild-2 in 2004 and return those samples to Earth in 2006. Deep Space 1, a mission under JPL's New Millennium program that is scheduled for launch in 1998, will fly by the asteroid McAuliffe and Comet West-Kohoutek-Ikemura in a demonstration of new spacecraft technologies.

      Telescope viewing of Comet Hale-Bopp will be available from 7:30 to 8:30 p.m. on the lawn west of Beckman Institute at the southeast corner of Lura Street at Wilson Avenue in Pasadena. In the event of rain or thick cloud cover, telescopes will not be available. The panel discussion will begin at 9 p.m. at Caltech's Beckman Auditorium, located on Michigan Avenue one block south of Del Mar Boulevard. Doors to Beckman will open at 8 p.m., and those attending the panel discussion must be seated by 8:45 p.m.

      "Comet Chasers: On the Trail of a Comet" is sponsored by JPL's Galileo and Stardust projects. JPL manages the Galileo mission for NASA's Office of Space Science. Stardust is a partnership between JPL, the University of Washington and Lockheed Martin Astronautics.

      A live simulcast of the panel discussion will be available over the Internet via CuSeeMe. Information on how to connect will be available on the Comet Hale-Bopp home page at or Additional information on Comet Hale-Bopp is at Information on the Stardust mission is at Information on the Galileo mission is at

3/31/97 SRZ