Kuiper Prize Going to JPL Pioneer in Radar Study of Asteroids

For his years of research demonstrating the power of radar techniques
to wrest information from near-Earth asteroids, Dr. Steven Ostro will
receive the prestigious Gerard P. Kuiper Prize next year from the
American Astronomical Society’s Division for Planetary Sciences.

Ostro studies asteroids as a senior research scientist at NASA’s Jet
Propulsion Laboratory, Pasadena, Calif. He began probing these
miniature planets with radar more than 20 years ago, and was
essentially the only researcher doing so through the 1980s. The field
has grown in the past decade, with increasing recognition of the
scientific importance of asteroids.

“Not only has Steve pioneered this field, he has trained a whole posse
of young scientists who are now helping to reveal these incredibly
fascinating worlds,” said Division for Planetary Sciences Chair Dr.
Richard Binzel, a planetary scientist at the Massachusetts Institute
of Technology, Cambridge.

“Steve has done groundbreaking work in a new area of solar system
exploration,” said the division’s 2001 chair, Dr. Mark Sykes, a
planetary scientist at the University of Arizona, Tucson. “With radar
imaging of asteroids, he has provided insights into the shapes and
collisional evolution of these very common solar system objects. He
does things we couldn’t do otherwise without sending a spacecraft, and
he works with an intensity and meticulousness that make him a good
model for all of us.”

Ostro and his colleagues have successfully obtained radar echoes from
nearly 200 asteroids, mostly ones that cross Earth’s orbit but also
including many in the main asteroid belt between Mars and Jupiter.
“Every single one of them is unique in its own way,” Ostro said. “It’s
been just one remarkable object after another.”

telescopes, radar experiments have revealed exotic shapes, such as the
dogbone configuration of asteroid Kleopatra and the elongated shape of
Geographos. They have disclosed unusual motions, such as the slow
wobbling of Toutatis. They have shown craters and other geological
features on asteroids’ surfaces. They have identified some asteroids
as metallic, some as unconsolidated heaps of rubble and some as pairs
orbiting each other while they orbit the Sun.

“I feel extremely fortunate to be doing this work,” Ostro said. “It’s
like a Star Trek fantasy — seeing a world that no one has ever seen
before. That’s what I’ve been able to do over and over.”

The radar experiments require large dish-shaped antennas, such as
those at the Goldstone, Calif., facilities of NASA’s Deep Space
Network, and the National Science Foundation’s Arecibo Observatory in
Puerto Rico. The Goldstone antennas serve primarily for communicating
with distance spacecraft and get additional use for radio astronomy,
including radar investigations. With radar, a radio signal is beamed
to the target, and the echo brings information about the object that
has reflected it.

“It’s not a passive observation like other areas of astronomy. It’s
more like performing an experiment on the object,” Ostro said. “We
stimulate the object to give up its secrets. We send out questions and
get back answers.”

Among the most important answers from any near-Earth asteroid are
exactly how far away it is and how fast it is traveling. That
information allows a much more precise calculation of its orbit than
is possible from only repeated optical observations of the same
asteroid. With orbital calculations that incorporate radar-observation
data, the forecast of the asteroid’s likelihood of striking Earth can
often be extended for centuries into the future. Earlier this year,
observations by Ostro and colleagues were used to show that an
asteroid named 1950 DA has a slight chance — possibly one in 300,
probably much less — of hitting Earth on Saturday, March 16, 2880,
which makes 1950 DA the most hazardous known asteroid. To date, NASA
has discovered about half of the estimated potentially hazardous
near-Earth asteroids, and, besides the extremely remote possibility of
1950 AD, none is on a path that will impact the Earth.

Near-Earth asteroids make inviting destinations for initial human
exploration of the solar system beyond the Moon, Ostro said. Many
would be relatively easy to reach and offer useful resources, such as
metals, complex organic compounds and chemically bound water, for
wider-ranging space exploration.

The prize Ostro will receive next September is named for Gerard
The 1,200-member Division for Planetary Sciences awards it to one
scientist each year “whose achievements have most advanced our
understanding of the planetary system.” Ostro will be the 20th
recipient. Previous winners have included Carl Sagan, James Van Allen
and Eugene Shoemaker. Ostro will be the first JPL scientist to receive
the Kuiper Prize. The California Institute of Technology’s Dr. Peter
Goldreich received it in 1992.

Ostro is a New Jersey native who earned bachelor’s degrees in liberal
arts and ceramic science from Rutgers University, New Brunswick, N.J.;
a master’s degree in engineering physics from Cornell University,
Ithaca, N.Y.; and a doctorate in planetary sciences from the
Massachusetts Institute of Technology. He began working at JPL in
1984.

The California Institute of Technology, Pasadena, manages JPL for
NASA.