NASA Scientists Get First Images of Earth Flyby Asteroid

MEDIA RELATIONS 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: DC Agle 818-393-9011
Jet Propulsion Laboratory, Pasadena, Calif.
agle@jpl.nasa.gov

Grey Hautaluoma 202-358-0668
Headquarters, Washington
grey.hautaluoma-1@nasa.gov

NEWS RELEASE: 2008-014 Jan. 25, 2008

NASA Scientists Get First Images of Earth Flyby Asteroid

Scientists at NASA's Jet Propulsion Laboratory in Pasadena, Calif., have obtained the
first images of asteroid 2007 TU24 using high-resolution radar data. The data indicate the
asteroid is somewhat asymmetrical in shape, with a diameter roughly 250 meters (800
feet) in size. Asteroid 2007 TU24 will pass within 1.4 lunar distances, or 538,000
kilometers (334,000 miles), of Earth on Jan. 29 at 12:33 a.m. Pacific time (3:33
a.m. Eastern time).

"With these first radar observations finished, we can guarantee that next week's 1.4-lunar-
distance approach is the closest until at least the end of the next century," said Steve
Ostro, JPL astronomer and principal investigator for the project. "It is also the asteroid's
closest Earth approach for more than 2,000 years."

Scientists at NASA's Near-Earth Object Program Office at JPL have determined that
there is no possibility of an impact with Earth in the foreseeable future.

Asteroid 2007 TU24 was discovered by the NASA-sponsored Catalina Sky Survey on
Oct. 11, 2007. The first radar detection of the asteroid was acquired on Jan. 23 using the
Goldstone 70-meter (230-foot) antenna. The Goldstone antenna is part of NASA's Deep
Space Network Goldstone station in Southern California's Mojave Desert. Goldstone's
70-meter diameter (230-foot) antenna is capable of tracking a spacecraft traveling more
than 16 billion kilometers (10 billion miles) from Earth. The surface of the 70-meter
reflector must remain accurate within a fraction of the signal wavelength, meaning that
the precision across the 3,850-square-meter (41,400-square-foot) surface is maintained
within one centimeter (0.4 inch).

Ostro and his team plan further radar observations of asteroid 2007 TU24 using the
National Science Foundation's Arecibo Observatory in Puerto Rico on Jan. 27-28 and
Feb. 1-4.

The asteroid will reach an approximate apparent magnitude 10.3 on Jan. 29-30 before
quickly becoming fainter as it moves farther from Earth. On that night, the asteroid will
be observable in dark and clear skies through amateur telescopes with apertures of at least
7.6 centimeters (three inches). An object with a magnitude of 10.3 is about 50 times
fainter than an object just visible to the naked eye in a clear, dark sky.

Scientists working with Ostro on the project include Lance Benner and Jon Giorgini
of JPL, Mike Nolan of the Arecibo Observatory, and Greg Black of the University of
Virginia.

NASA detects and tracks asteroids and comets passing close to Earth. The Near Earth
Object Observation Program, commonly called "Spaceguard," discovers, characterizes
and computes trajectories for these objects to determine if any could be potentially
hazardous to our planet. The Arecibo Observatory is part of the National Astronomy
and Ionosphere Center, a national research center operated by Cornell University, Ithaca,
N.Y., for the National Science Foundation. JPL is a division of the California Institute of
Technology in Pasadena.

For more information, visit http://neo.jpl.nasa.gov .

-end-

To remove yourself from all mailings from NASA Jet Propulsion Laboratory, please go to http://www.kintera.org/TR.asp?a=drJNL0OBJcKPL9I&s=ddJOKMOlG9IAKLPrEnF&m=fpKPJTMtFfLWF