Minor planet · Trojan · (588) Achilles
588 Achilles
The first Jupiter Trojan discovered, leading Jupiter at the L4 Lagrange point in the 'Greek camp'.
Asteroids
Orbit & physical parameters
Osculating orbit and physical parameters from the NASA JPL Small-Body Database · Jupiter Trojan · epoch 2026-06-09 (JD 2461200.5 TDB) · Earth MOID 3.46956 au
| Semi-major axis | 5.215907 ± 2.7240e-8 au | NASA JPL · calculated |
| Eccentricity | 0.148118 ± 5.2157e-9 | NASA JPL · calculated |
| Perihelion distance | 4.44334 ± 5.0107e-8 au | NASA JPL · calculated |
| Aphelion distance | 5.988474 ± 3.1274e-8 au | NASA JPL · calculated |
| Inclination | 10.315073 ± 7.6322e-8 deg | NASA JPL · calculated |
| Longitude of ascending node | 316.529891 ± 4.6395e-7 deg | NASA JPL · calculated |
| Argument of perihelion | 134.314643 ± 1.4586e-6 deg | NASA JPL · calculated |
| Orbital period | 4,351 ± 3.4085e-5 d | NASA JPL · calculated |
| Diameter | 130.099 ± 0.554 km | NASA JPL · catalogued |
| Geometric albedo | 0.043 ± 0.006 | NASA JPL · estimated |
| Rotation period | 7.306 h | NASA JPL · catalogued |
| Absolute magnitude (H) | 8.2 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 Otto Matic, 5742 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 Otto Matic, 5742 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 Otto Matic, 5742 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 Otto Matic, 5742 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 Otto Matic, 5742 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 Otto Matic, 5742 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 Otto Matic, 5742 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 Otto Matic, 5742 obs · retrieved 2026-07-11
- Diameter: Jet Propulsion Laboratory / Solar System Dynamics · JPL SBDB · phys_par · phys.diameter · catalogued value · JPL solution by Otto Matic, 5742 obs · retrieved 2026-07-11
- Geometric albedo: Jet Propulsion Laboratory / Solar System Dynamics · JPL SBDB · phys_par · phys.albedo · Bayesian estimate · JPL solution by Otto Matic, 5742 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 Otto Matic, 5742 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 Otto Matic, 5742 obs · retrieved 2026-07-11
Orbital elements are a calculated JPL orbit-determination fit, all referred to the single osculating epoch above (solution by Otto Matic); each carries its own uncertainty. Fields the database did not provide are omitted, never invented.
Populations
Knowledge connections
- Member of groupGreek Camp (L4)
- Member of groupJupiter Trojans
- In orbital resonance1:1 resonance with Jupiter
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.