http://www.c3.lanl.gov/~cjhamil/SolarSystem/toutatis.html (Einblicke ins Internet, 10/1995)
Toutatis
(GIF, 110K)
Asteroid 4179 Toutatis, an Earth-crossing asteroid,
made a close approach to the Earth in December 1992.
At the time, Toutatis was an average of about 4
million kilometers (2.5 million miles) from Earth.
Images of Toutatis were acquired using radar carried out at the
Goldstone Deep Space Communications Complex in
California's Mojave desert. For most of the work, a 400,000-watt
coded radio
transmission was beamed at Toutatis from the Goldstone main 70-meter
(230-foot) antenna. The echoes, which took as little as 24
seconds to travel to Toutatis and back, were received by the new
34-meter (112-foot) antenna and relayed back to the 70-meter
station where they were decoded and processed into images.
The images of Toutatis reveal two
irregularly shaped, cratered objects about 4 and 2.5 kilometers
(2.5 and 1.6 miles) in average diameter which are probably in
contact with each other. These "contact binaries" may be fairly
common since another one, 4769 Castalia,
was observed in 1989 when it passed near the Earth.
The above image shows one of the four frames that were obtained on
December 8th through the 13th. For a full view click on the above
image. On each day, the asteroid was in a
different orientation with respect to Earth. One large crater can
be seen in the December 9th image that measures about 700
meters (2,300 feet) in diameter.
Asteroids
Ida
Castalia
Copyright © 1995 by
Calvin J. Hamilton. All rights reserved.
Last Modified: March 2, 1995