Phobos
Mars 401 Phobos
📋 A written introduction is coming — for now this page shows official values only.
Physical data
- Mean radius
- 11.08 km
- GM
- 0.000709 km³/s²
- Density
- 1.872 g/cm³
Source:NASA JPL Solar System Dynamics · checked 2026-11-02 ↗
Orbit
- Semi-major axis
- 9,375 km
- Eccentricity
- 0.015
- Inclination
- 1.1°
- Orbital period
- 0.3187 days
- Retrograde
- No
Source:NASA JPL Solar System Dynamics · checked 2026-11-02 ↗
Related
Parent body
In everyday life
- About 22 km across — 5.5% of the 400 km Seoul–Busan expressway.
- One orbit takes about 7.6 hours — more than 3.1 orbits a day.
- About 9,375 km from Mars on average — 23 drives along the 400 km Seoul–Busan expressway.