In the study of asteroids, a contact binary is caused when two asteroids gravitate toward each other until they touch, forming an oddly-shaped single body. Asteroids suspected of being contact binaries include the unusually elongated 624 Hektor

624 Hektor

624 Hektor is the largest Jupiter Trojan. It was discovered in 1907 by August Kopff.Hektor is a D-type asteroid, dark and reddish in colour. It lies in Jupiter's leading Lagrangian point, , called the 'Greek' node after one of the two sides in the legendary Trojan War...

 and the bilobated 216 Kleopatra

216 Kleopatra

216 Kleopatra is a trinary main-belt asteroid that was discovered by Johann Palisa on April 10, 1880, in Pola. It is named after Cleopatra, Queen of Ancient Egypt....

 and 4769 Castalia

4769 Castalia

The asteroid 4769 Castalia was the first asteroid to be modeled by radar imaging. It is an Apollo, Mars- and Venus-crosser asteroid. It was discovered on August 9, 1989, by Eleanor F. Helin on photographic plates taken at Palomar Observatory...

. 25143 Itokawa

25143 Itokawa

25143 Itokawa is an Apollo and Mars-crosser asteroid. It was the first asteroid to be the target of a sample return mission, the Japanese space probe Hayabusa.-Discovery and naming:...

, recently photographed by the Hayabusa

Hayabusa

was an unmanned spacecraft developed by the Japan Aerospace Exploration Agency to return a sample of material from a small near-Earth asteroid named 25143 Itokawa to Earth for further analysis....

probe, also appears to be a contact binary which has resulted in an elongated, bent body.