[meteorite-list] Asteroid Toutatis Slowly Tumbles by Earth

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Sat, 15 Dec 2012 19:15:04 -0800 (PST)
Message-ID: <201212160315.qBG3F4fh014604_at_zagami.jpl.nasa.gov>

http://www.jpl.nasa.gov/news/news.php?release=2012-397

Asteroid Toutatis Slowly Tumbles by Earth
Jet Propulsion Laboratory
December 14, 2012

Scientists working with NASA's 230-foot-wide (70-meter) Deep Space Network antenna
at Goldstone, Calif., have generated a series of radar data images of a
three-mile-long (4.8-kilometer) asteroid that made its closest approach to Earth
on Dec. 12, 2012. The radar data images of asteroid Toutatis have been assembled
into a short movie, available online at:
http://www.jpl.nasa.gov/video/index.php?id=1175 .

The images that make up the movie clip were generated with data taken
on Dec. 12 and 13, 2012. On Dec. 12, the day of its closest approach to
Earth, Toutatis was about 18 lunar distances, 4.3 million miles (6.9 million
kilometers) from Earth. On Dec. 13, the asteroid was about 4.4 million
miles (7 million kilometers), or about 18.2 lunar distances.

The radar data images of asteroid Toutatis indicate that it is an elongated,
irregularly shaped object with ridges and perhaps craters. Along with shape
detail, scientists are also seeing some interesting bright glints that could be
surface boulders. Toutatis has a very slow, tumbling rotational state.
The asteroid rotates about its long axis every 5.4 days and precesses
(changes the orientation of its rotational axis) like a wobbling, badly
thrown football, every 7.4 days.

The orbit of Toutatis is well understood. The next time Toutatis will approach at
least this close to Earth is in November of 2069, when the asteroid will safely fly
by at about 7.7 lunar distances, or 1.8 million miles (3 million kilometers). An
analysis indicates there is zero possibility of an Earth impact over the entire interval
over which its motion can be accurately computed, which is about the next
four centuries.

This radar data imagery will help scientists improve their understanding of the
asteroid's spin state, which will also help them understand its interior.

The resolution in the image frames is 12 feet (3.75 meters) per pixel.

NASA detects, tracks and characterizes asteroids and comets passing close to Earth
using both ground- and space-based telescopes. The Near-Earth Object Observations
Program, commonly called "Spaceguard," discovers these objects, characterizes a subset
of them, and plots their orbits to determine if any could be potentially hazardous
to our planet.

JPL manages the Near-Earth Object Program Office for NASA's Science Mission Directorate
in Washington. JPL is a division of the California Institute of Technology in Pasadena.

D.C. Agle 818-393-9011
Jet Propulsion Laboratory, Pasadena, Calif.
agle at jpl.nasa.gov

2012-397
Received on Sat 15 Dec 2012 10:15:04 PM PST