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 RELEASE
November 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
#####
[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
#9689
