Astronomical specifications:
| Discovery | 1610 by Galileo |
| Orbital characteristics: | |
| Distance from Jupiter | 1,070,400 km |
| Eccentricity | 0.0013 |
| Orbital periode about Jupiter | 7.154 days |
| Orbital speed | 10.880 km/s |
| Inclination to Jupiter equator | 1.85 deg |
| Rings | No |
| Physical characteristics: | |
| Radius | 2,634 km |
| Surface area | 87,000,000 km² |
| Volume | 7.6 x 1010 km³ |
| Mass | 1.4819 x 1023 kg |
| Density | 1.936 g/cm³ |
| Equatorial gravity | 1.428 m/s² |
| Escape velocity | 2.741 km/s |
| Rotation period | 7.154 days |
| Axial tilt | 0-0.33 deg |
| Surface temperature | 110 K |
| Atmospheric composition | O2 |
A true color image of Ganymede acquired by the Galileo spacecraft (taken on June 26, 1996). (NASA/JPL image)