contact binary
英[ˈkɔntækt ˈbaɪnəri:]美[ˈkɑnˌtækt ˈbaɪnəri]
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 and the [216 Kleopatra] and [[4769 Castalia.