Contact binary (small Solar System body)

Contact binaries of varying probability among the small Solar System bodies:

• Top-Left: Kuiper belt object 486958 Arrokoth photographed by the New Horizons probe
• Top-Right: Comet 67P/Churyumov–Gerasimenko, with two distinct lobes connected by a "neck" as seen by the Rosetta probe
• Bottom-Left: Main-belt asteroid 52246 Donaldjohanson photographed by the Lucy probe
• Bottom-Right: Main-belt asteroid 152830 Dinkinesh and its contact binary satellite Selam photographed by Lucy

A contact binary is a small Solar System body, such as a minor planet or comet, that is composed of two bodies that have gravitated toward each other until they touch, resulting in a bilobated, peanut-like overall shape. Contact binaries are distinct from true binary systems such as binary asteroids where both components are separated. The term is also used for stellar contact binaries.

An example of a contact binary is the Kuiper belt object 486958 Arrokoth, which was imaged by the New Horizons spacecraft during its flyby in January 2019.