← ALL BRIEFINGS

Dimorphos

← ALL CELESTIAL BODIES
Credit: NASA/JHUAPL Public domain — NASA Media Usage Guidelines
ASTEROID

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.

Physical Properties

0 km
11.921 h
0.15

Orbit

Didymos
0.4974 d

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: 2026-04-18 18:19:27.

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.