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PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
http://www.jpl.nasa.gov

Contact: Jane Platt

FOR IMMEDIATE RELEASENovember 27, 1996

ODDBALL ASTEROID CAPTURED ON NEW VIDEO COMPUTER SIMULATION

       A new computer-generated video visualization is giving planetary scientists a fresh look at the topsy-turvy rotation of the intriguing asteroid Toutatis, which is due to pass near Earth on November 29.

       Dr. Eric De Jong and animator Shigeru Suzuki of NASA's Jet Propulsion Laboratory, combined several computer simulation and scientific visualization techniques to show the bizarre rotation and surface details of Toutatis as it tumbles erratically on its journey around the Sun. The video includes images of Toutatis from various vantage points, including the perspective of someone standing on its surface. In addition, trajectories and explosive surface impacts are shown for a more typical near-Earth asteroid, named Castalia.

       The animation was created at the JPL Digital Image Animation Laboratory (DIAL) from a model based on a previous sequence of delay-Doppler radar images. Those images were recorded at NASA's Deep Space Network 70-meter (230-foot) and 34-meter (112-foot) radio/radar antennas in Goldstone, CA, and the 305-meter (1,000- foot) Arecibo Radio Telescope in Puerto Rico.

       "It's amazing that the shape of Toutatis can be determined so accurately from ground-based observations," De Jong said. "This technology will provide us with startling, close-up views of thousands of asteroids that orbit near the Earth."

       Dr. Scott Hudson of Washington State University, Pullman, WA, collaborated on the venture, along with scientists at NASA's Ames Research Center, Mountain View, CA. "We used the computer to mathematically create a three- dimensional model of the surface and rotation of Toutatis," Hudson said. "It's as though we put a clay model in space and molded it until it matched the appearance of the actual asteroid."

       The video is of particular interest as Toutatis nears Earth and makes its closest approach on Friday, November 29, when it will pass by at a distance of 5.3 million kilometers (3.3 million miles), or about 14 times the distance from the Earth to the Moon. In 2004, Toutatis will pass only four lunar distances from Earth, closer than any known Earth-approaching object expected to pass by in the next 60 years.

       However, "Toutatis poses no significant threat to Earth, at least for a few hundred years," according to JPL senior research scientist Dr. Steven Ostro, who observed Toutatis in 1992 and is studying the asteroid once again this week at Goldstone.

       Discovered in 1989 and named after a Celtic god, the asteroid Toutatis has dimensions of 4.6 by 2.4 by 1.9 kilometers (2.9 by 1.5 by 1.2 miles). It is considered one of the strangest bodies in the Solar System, given its peculiar rotation and odd shape, which resembles two chunks of rock connected by a narrow neck-like structure. The rocky body's strange traits are believed to be the result of a history of violent collisions.

       Asteroids, sometimes known as minor planets, are small orbiting bodies composed of rock and metals. They hold special fascination for scientists because of their age, quantity and proximity to the Earth. Scientists estimate that there are more than 100,000 near-Earth asteroids larger than a football stadium.

       "The discovery that we live in an asteroid swarm is important for the future of humanity," said Ostro. "These leftover debris from planetary formation can teach us a good deal about the formation of our Solar System. Asteroids also contain valuable minerals and many are the cheapest possible destinations for space missions."

       For example, a flyby of the asteroid McAuliffe is planned by the first flight mission in NASA's New Millennium program, which is designed to test and apply new technologies for future space science and Earth science missions. New Millennium is managed by JPL for NASA's Offices of Space Science and Mission to Planet Earth, Washington, DC.

       In addition, NASA's Near Earth Asteroid Rendezvous (NEAR) mission, launched in February 1996, is en route to the asteroid Eros, which it will orbit beginning in January 1999.

       Additional information on Toutatis and other asteroids is available at the following websites:
http://echo.jpl.nasa.gov
http://www.eecs.wsu.edu/~hudson/asteroids.html
http://photojournal.jpl.nasa.gov

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[Note to Editors: The video animation of Toutatis will air at 9 a.m., noon, 3 p.m. and 6 p.m. Pacific time today on NASA TV and is also available by calling the JPL Public Information Office. Stills are also available.]

11/22/96 JP
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