1982 TA was discovered on October 11, 1982, by Eleanor F. Helin

Eleanor F. Helin

Eleanor Francis "Glo" Helin was an American astronomer. She was principal investigator of the Near Earth Asteroid Tracking program of NASA's Jet Propulsion Laboratory. Some sources give her name as Eleanor Kay Helin...

 and Eugene Shoemaker. It is an Apollo

Apollo asteroid

The Apollo asteroids are a group of near-Earth asteroids named after 1862 Apollo, the first asteroid of this group to be discovered by Karl Wilhelm Reinmuth...

, Mars-

Mars-crosser asteroid

A Mars-crosser is an asteroid whose orbit crosses that of Mars. The known numbered Mars-crossers are listed here. They include the two numbered Mars trojans 5261 Eureka and ....

 and Venus-crosser asteroid

Venus-crosser asteroid

A Venus-crosser is an asteroid whose orbit crosses that of Venus. The known numbered Venus-crossers and outer-grazers are listed below .Venus also has a quasi-satellite, 2002 VE68...

, only 1.7 km in diameter.

In 1996, astronomers at the Goldstone Observatory analysed it using radar

Radar

Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...

 delay-Doppler imaging

Dopplergraph

The word dopplergraph is a combination of the words doppler  and photograph . Just as a photograph is a two-dimensional record of variations in light intensity, a dopplergraph is a two dimensional record of variations in the doppler shift in light intensity...

. The resultant images are not very clear, but they show that (4197) 1982 TA has a roughly triangular shape, and a 3-hour rotation period.