Table 1 General characteristics of Phobos
From: Surface environment of Phobos and Phobos simulant UTPS
| Parameter | Value | References |
|---|---|---|
| Dimension | 26.06 × 22.80 × 18.28 km | Willner et al. (2014) |
| Mean radius | 10.993 km | Willner et al. (2014) |
| Mass | 1.0668 ± 0.003 × 1016 kg | Andert et al. (2010) |
| 1.065 ± 0.015 × 1016 kg | Pätzold et al. (2014) | |
| 1.0604 ± 0.0011 × 1016 kg | Yang et al. (2019) | |
| Volume | 5742 ± 35 km3 | Willner et al. (2014) |
| Surface area | 1567.9 km2 | |
| Mean density | 1.860 ± 0.013 g/cm3 | Willner et al. (2014) |
| 1.846 ± 0.011 g/cm3 | Yang et al. (2019) | |
| Surface gravity | 0.003–0.007 m/s2 | Thomas (1993) |
| Escape velocity | 11.39 m/s | |
| Rotation period | 7 h 39 min 19.47 s | Jacobson (2010) |
| Semi-major axis of the orbit | 9375 km (2.76 Mars radii) | Jacobson (2010) |
| Mean orbital velocity | 2.138 km/s | Jacobson (2010) |
| Equatorial rotation velocity | 2.97 m/s | |
| Eccentricity | 0.0151 | Jacobson (2010) |
| Inclination | 1.0847 deg to Mars’ equator | Jacobson (2010) |
| 1.0756 deg to local Laplace plane | ||
| 26.04 deg to the ecliptic plane | ||
| Geometric albedo | 0.071 | Simonelli et al. (1998) |
| IR emissivity | 0.98 | |
| Thermal inertia | 20–70 Jm−2 K−1 s−1/2 | Lunine et al. (1982), Kührt et al. (1992) |
| Surface slope | 0–40 degree | Willner et al. (2014), Wang and Wu (2020) |
| Dust deposition rate | 14–26 µm/year | |
| Dust electric charge | 10–16 C/particle | Senshu et al. (2015) |
| Small meteorite flux | 10–16 g/cm2/s | Grün et al. (1985), Divine (1993) |
| Meteorite impact velocity | 8.5–15 km/s | Divine (1993) |
| Internal thermal flux | 0.0 W/m2 | |
| Surface temperature | 60–330 K @N ± 60° | Kührt and Giese (1989) |