Dimorphos

The asteroid moonlet struck by NASA DART — the first object whose orbit has been changed by humans.

Orbits Didymos

Struck by NASA DART on 26 September 2022 at 6.14 km/s u2014 the first deliberate alteration of a Solar System body's orbit by humans.
Orbital period around Didymos shortened by 33 minutes after impact.
Will be characterized up-close by ESA Hera in 2026-2027.

About Dimorphos

Dimorphos is a ~170 m “moonlet” of the larger asteroid Didymos. On 26 September 2022 at 23:14 UTC, NASA’s DART spacecraft deliberately impacted Dimorphos at 6.14 km/s, shortening its orbital period around Didymos by 33 ± 1 minutes — the first time humans have intentionally changed the orbit of a celestial body, and a proof-of-concept for planetary-defense deflection.

Physical Properties

Mean radius0 km

Rotation period11.921 h

Bond albedo0.15

Orbit

OrbitsDidymos

Orbital period0.4974 d

Gallery

Hand-picked mission imagery of Dimorphos sourced from NASA and partner archives. Click any photo for full resolution and source attribution.

The asteroid moonlet Dimorphos, imaged by NASA's DART spacecraft just before impact. NASA/Johns Hopkins APL · Public Domain u2014 NASA Media Usage Guidelines

Imagery on this page is provided by the original mission teams. Full attribution terms: Image Rights & Credits.

Sources & Further Reading

Numerical values (radius, mass, orbital elements, temperatures) are drawn from NASA NSSDC Planetary Fact Sheets, JPL Horizons, and the JPL Small-Body Database. Last refreshed: 2026-06-08 01:37:02.