163693 Atira
The prototype of the Atira class — near-Earth asteroids whose orbits lie entirely inside Earth's orbit — and itself a binary system.
Orbit & physical parameters
Osculating orbit and physical parameters from the NASA JPL Small-Body Database · Atira · near-Earth · epoch 2026-06-09 (JD 2461200.5 TDB) · Earth MOID 0.207318 au
| Semi-major axis | 0.740958 ± 1.0267e-9 au | NASA JPL · calculated |
| Eccentricity | 0.322162 ± 9.4587e-8 | NASA JPL · calculated |
| Perihelion distance | 0.50225 ± 7.0003e-8 au | NASA JPL · calculated |
| Aphelion distance | 0.979667 ± 1.3574e-9 au | NASA JPL · calculated |
| Inclination | 25.618888 ± 1.0689e-5 deg | NASA JPL · calculated |
| Longitude of ascending node | 103.86784 ± 1.9647e-5 deg | NASA JPL · calculated |
| Argument of perihelion | 252.927897 ± 8.0281e-6 deg | NASA JPL · calculated |
| Orbital period | 232.964156 ± 4.8420e-7 d | NASA JPL · calculated |
| Rotation period | 3.398 h | NASA JPL · catalogued |
| Absolute magnitude (H) | 16.41 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, 1080 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, 1080 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, 1080 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, 1080 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, 1080 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, 1080 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, 1080 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, 1080 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, 1080 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, 1080 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.
Knowledge connections
- Member of groupAtira asteroids
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.