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JET PROPULSION LABORATORY

CALIFORNIA INSTITUTE OF TECHNOLOGY

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Contact: Jane Platt

INTERNET IMAGE ADVISORY

New images taken by the camera onboard the Saturn-bound Cassini spacecraft
are giving scientists the first size estimates on asteroid 2685 Masursky
and preliminary evidence that it may have different material properties
than previously believed.

“The Masursky images represent the first time that Cassini has gathered
information on a body not extensively studied from Earth,” said Carolyn C.
Porco, Cassini imaging team leader and associate professor at the Lunar and
Planetary Laboratory of the University of Arizona, Tucson.

The images, taken on Jan. 23, also marked the first use of Cassini’s
automated object-targeting capabilities, and they functioned as expected,
Porco said. The two new images are available at the following websites:
http://www.jpl.nasa.gov/pictures/cassini and http://ciclops.lpl.arizona.edu
.

Launched October 15, 1997, Cassini flew by Venus and Mars before heading
toward a flyby of Jupiter next December. It entered the asteroid belt
between Mars and Jupiter, a region populated by asteroids, in mid-November
of 1999.

Cassini’s camera took pictures of the asteroid when the spacecraft was 7
hours and 5-1/2 hours before closest approach, at a distance of 1.6 million
kilometers (960,000 miles). Since Masursky is too small to be measured
from Earth, scientists hoped Cassini could help them determine its size, as
well as its reflectivity, asteroid category, and possibly its rotation period.

“So far, the images reveal that the side of Masursky imaged by Cassini is
roughly 15 to 20 kilometers (9 to 12 miles) across,” Porco said.

The Cassini spacecraft is scheduled to arrive at Saturn in July 2004 to
begin a four-year exploration of the ringed planet and its moons. The
Cassini mission is managed by NASA’s Jet Propulsion Laboratory in Pasadena,
Calif., for NASA’s Office of Space Science, Washington, D.C. JPL is a
division of the California Institute of Technology in Pasadena.

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