65803 Didymos
A near-Earth binary asteroid whose small moon, Dimorphos, was struck by NASA's DART in 2022 — humanity's first test of asteroid deflection.
Orbit & physical parameters
Osculating orbit and physical parameters from the NASA JPL Small-Body Database · Apollo · near-Earth · potentially hazardous · epoch 2026-06-09 (JD 2461200.5 TDB) · Earth MOID 0.039575 au
| Semi-major axis | 1.64271 ± 9.9148e-11 au | NASA JPL · calculated |
| Eccentricity | 0.383123 ± 1.0416e-10 | NASA JPL · calculated |
| Perihelion distance | 1.013349 ± 1.7330e-10 au | NASA JPL · calculated |
| Aphelion distance | 2.27207 ± 1.3713e-10 au | NASA JPL · calculated |
| Inclination | 3.413877 ± 1.4820e-8 deg | NASA JPL · calculated |
| Longitude of ascending node | 72.985824 ± 1.9715e-7 deg | NASA JPL · calculated |
| Argument of perihelion | 319.5807 ± 2.1543e-7 deg | NASA JPL · calculated |
| Orbital period | 769.023521 ± 6.9623e-8 d | NASA JPL · calculated |
| Diameter | 0.78 ± 0.03 km | NASA JPL · catalogued |
| Rotation period | 2.2593 h | NASA JPL · catalogued |
| Absolute magnitude (H) | 18.11 mag | NASA JPL · catalogued |
Full field-level provenance
- Semi-major axis: Jet Propulsion Laboratory / Solar System Dynamics · JPL SBDB · orbit.elements · a · JPL orbit determination (least-squares fit to the observation arc) · calculated · JPL solution by Steve Chesley, 1869 obs · retrieved 2026-07-11
- Eccentricity: Jet Propulsion Laboratory / Solar System Dynamics · JPL SBDB · orbit.elements · e · JPL orbit determination (least-squares fit to the observation arc) · calculated · JPL solution by Steve Chesley, 1869 obs · retrieved 2026-07-11
- Perihelion distance: Jet Propulsion Laboratory / Solar System Dynamics · JPL SBDB · orbit.elements · q · JPL orbit determination (least-squares fit to the observation arc) · calculated · JPL solution by Steve Chesley, 1869 obs · retrieved 2026-07-11
- Aphelion distance: Jet Propulsion Laboratory / Solar System Dynamics · JPL SBDB · orbit.elements · ad · JPL orbit determination (least-squares fit to the observation arc) · calculated · JPL solution by Steve Chesley, 1869 obs · retrieved 2026-07-11
- Inclination: Jet Propulsion Laboratory / Solar System Dynamics · JPL SBDB · orbit.elements · i · JPL orbit determination (least-squares fit to the observation arc) · calculated · JPL solution by Steve Chesley, 1869 obs · retrieved 2026-07-11
- Longitude of ascending node: Jet Propulsion Laboratory / Solar System Dynamics · JPL SBDB · orbit.elements · om · JPL orbit determination (least-squares fit to the observation arc) · calculated · JPL solution by Steve Chesley, 1869 obs · retrieved 2026-07-11
- Argument of perihelion: Jet Propulsion Laboratory / Solar System Dynamics · JPL SBDB · orbit.elements · w · JPL orbit determination (least-squares fit to the observation arc) · calculated · JPL solution by Steve Chesley, 1869 obs · retrieved 2026-07-11
- Orbital period: Jet Propulsion Laboratory / Solar System Dynamics · JPL SBDB · orbit.elements · per · JPL orbit determination (least-squares fit to the observation arc) · calculated · JPL solution by Steve Chesley, 1869 obs · retrieved 2026-07-11
- Diameter: Jet Propulsion Laboratory / Solar System Dynamics · JPL SBDB · phys_par · phys.diameter · catalogued value · JPL solution by Steve Chesley, 1869 obs · retrieved 2026-07-11
- Rotation period: Jet Propulsion Laboratory / Solar System Dynamics · JPL SBDB · phys_par · phys.rot_per · catalogued value · JPL solution by Steve Chesley, 1869 obs · retrieved 2026-07-11
- Absolute magnitude (H): Jet Propulsion Laboratory / Solar System Dynamics · JPL SBDB · phys_par · phys.H · catalogued value · JPL solution by Steve Chesley, 1869 obs · retrieved 2026-07-11
Orbital elements are a calculated JPL orbit-determination fit, all referred to the single osculating epoch above (solution by Steve Chesley); each carries its own uncertainty. Fields the database did not provide are omitted, never invented.
Exploration
Knowledge connections
- Member of groupApollo asteroids
- Visited byDART
- TargetsHera
- Orbited byDimorphos
- Visited byDART
Sources
The primary and reference sources this topic draws on.
- NASANational Aeronautics and Space Administration
Mission data, planetary science, space telescopes, and public-domain imagery.
Most NASA-produced imagery is in the public domain; individual items are checked for usage terms before publication.
- NASA JPLJet Propulsion Laboratory / Solar System Dynamics
Orbital data, ephemerides, and small-body parameters for planets, asteroids, and comets.