Paula Cleggett-Haleim
Headquarters, Washington, D.C.                                                      
October 5, 1992
(Phone:  202/358-1547)

Jim Doyle
Jet Propulsion Laboratory, Pasadena, Calif.
(Phone:  818/354-5011)


RELEASE:  92-164

Asteroid's Orbit "Closes In" on Earth

     One of the largest near-Earth objects, an asteroid named 
"Toutatis," will make a close Earth approach on Dec. 8, 1992, 
passing by at about 2.2 million miles (3.6 million kilometers) 
distance.

     Dr. Donald Yeomans, Head of the Near Earth Object Center at 
NASA's Jet Propulsion Laboratory, Pasadena, Calif., said the 
object, formally known as Asteroid 4179 Toutatis, passes Earth 
less than one degree above Earth's orbital plane every 4 years, 
making it an excellent object for study.  The asteroid, at 2 miles 
(3.5 kilometers) diameter, is one of the largest to cross the 
Earth's orbit on a regular basis.

     Yeomans said the ground-based viewing conditions will be 
excellent for infrared optical and radar observations just before, 
during and well after the close Earth passage, and he notes that 
astronomers in many areas of the world simultaneously will study 
the body using several different techniques.

     Toutatis again will make close Earth approaches in 1996 and 
2000.  In 2004, it will come as close as about four Earth-Moon 
distances or about a million miles (about 1.6 million kilometers).  
Its orbit takes it almost to the distance of Jupiter's orbit 
before the sun's gravitational attraction pulls it back.

     The approach of Toutatis this year and the one in 2004 
represent the two closest Earth passages of any known asteroid for 
the next 30 years, said Yeomans.

     Toutatis was discovered Jan. 4, 1989, by Astronomer Christian 
Pollas at Caussols, France, and was named after a Gallic deity 
called "protector of the tribe."

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