UPSA
Object Registry
Horizons 899
| Parameter | Value | Unit | Uncertainty | As published | Source | Reference |
|---|---|---|---|---|---|---|
| Mass | 102.409 | 1e24 kg | Mass x10^24 (kg) | JPL Horizons | JPL Horizons on-line ephemeris system | |
| Mean radius | 24,624 | km | Vol. mean radius (km) | JPL Horizons | JPL Horizons on-line ephemeris system | |
| Equatorial radius | 24,766 | Equat. radius (1 bar) | JPL Horizons | JPL Horizons on-line ephemeris system | ||
| Density | 1.638 | g/cm^3 | Density (g/cm^3) | JPL Horizons | JPL Horizons on-line ephemeris system | |
| Orbital period | 60,189 | d | Sidereal orbit period | JPL Horizons | JPL Horizons on-line ephemeris system | |
| Rotation period | 16.11 | Sid. rot. period (III) | JPL Horizons | JPL Horizons on-line ephemeris system | ||
| Geometric albedo | 0.41 | Geometric Albedo | JPL Horizons | JPL Horizons on-line ephemeris system | ||
| Escape velocity | 23.5 | km/s | Escape speed (1 bar) | JPL Horizons | JPL Horizons on-line ephemeris system | |
| GM | 6,835,100 | km^3/s^2 | GM (km^3/s^2) | JPL Horizons | JPL Horizons on-line ephemeris system | |
| Mean temperature | 72 | Atmos. temp. (1 bar) | JPL Horizons | JPL Horizons on-line ephemeris system | ||
| Obliquity to orbit | 28.32 | deg | Obliquity to orbit | JPL Horizons | JPL Horizons on-line ephemeris system | |
| Mean solar day | ~16.11 h | h | Mean solar day, h | JPL Horizons | JPL Horizons on-line ephemeris system | |
| Surface gravity | 11.15 | m/s^2 | Equ. grav, ge (m/s^2) | JPL Horizons | JPL Horizons on-line ephemeris system | |
| Aroche ice rp | 2.98 | Aroche(ice)/Rp | JPL Horizons | JPL Horizons on-line ephemeris system | ||
| Dg d mean orbit velocity | 5.43 | km/s | dg/d Mean orbit velocity | JPL Horizons | JPL Horizons on-line ephemeris system | |
| Flattening | 0.0171 | Flattening | JPL Horizons | JPL Horizons on-line ephemeris system | ||
| Hill s sphere rad rp | 4,700 | Hill's sphere rad., Rp | JPL Horizons | JPL Horizons on-line ephemeris system | ||
| Pol grav gp m s 2 | 11.41 | m/s^2 | Pol. grav, gp (m/s^2) | JPL Horizons | JPL Horizons on-line ephemeris system | |
| Polar radius km | 24,342 | km | Polar radius (km) | JPL Horizons | JPL Horizons on-line ephemeris system | |
| Sid rot rate rad s | 0.000108338 | rad/s | Sid. rot. rate (rad/s) | JPL Horizons | JPL Horizons on-line ephemeris system | |
| Vis mag opposition | 7.84 | Vis. mag. (opposition) | JPL Horizons | JPL Horizons on-line ephemeris system | ||
| Visual magnitude v 1 0 | -6.87 | Visual magnitude V(1,0) | JPL Horizons | JPL Horizons on-line ephemeris system | ||
| Volume 10 10 km 3 | 6,254 | Volume, 10^10 km^3 | JPL Horizons | JPL Horizons on-line ephemeris system |
| Archive | Read at (UTC) | Record |
|---|---|---|
| JPL Horizons | 2026-08-14 17:11 | open at source |
Machine-readable: /api/v1/object/neptune · Registry entry updated 2026-08-14.