Table 5.
Probabilities and Estimated Viable Transfers over the Past 3.5 Gyr to Some of the Moons in the Outer Solar System
| Destination | Impact ratio | Probability (%) | 3.5 Gyr total | Mass transfer (kg) | |
|---|---|---|---|---|---|
| from Earth |
Io |
7,300±900 |
5.7×10−6±7.0×10−7 |
10±1 |
3,800,000 |
| |
Europa |
15,000±2,000 |
2.8×10−6±5.0×10−7 |
6±0.9 |
1,900,000 |
| |
Ganymede |
13,000±2,000 |
3.1×10−6±5.0×10−7 |
6±1 |
2,100,000 |
| |
Callisto |
76,000±30,000 |
5.4×10−7±2.0×10−7 |
1±0.4 |
370,000 |
| |
Enceladus |
14,000±10,000 |
5.0×10−7±4.0×10−7 |
1±0.7 |
340,000 |
| |
Titan |
9,200±5,000 |
7.5×10−7±4.0×10−7 |
1±0.9 |
510,000 |
| from Mars |
Io |
7,300±900 |
5.4×10−6±6.0×10−7 |
40±5 |
15,000,000 |
| |
Europa |
15,000±2,000 |
2.7×10−6±4.0×10−7 |
20±4 |
7,200,000 |
| |
Ganymede |
13,000±2,000 |
3.0×10−6±5.0×10−7 |
20±4 |
8,100,000 |
| |
Callisto |
76,000±30,000 |
5.2×10−7±2.0×10−7 |
4±2 |
1,400,000 |
| |
Enceladus |
14,000±10,000 |
<1.8×10−7 |
<1.4 |
<490,000 |
| Titan | 9,200±5,000 | <2.7×10−7 | <2.1 | <730,000 |
The impact ratio is the number of meteoroids that hit the planet (Jupiter or Saturn) for each one that hits the moon. For transfer from Mars to Saturn's moons, upper limits are used. The mass transfer rates are estimated by assuming that each transferred fragment is a sphere 3 m in diameter, with a density of 3 g/cm3, i.e., a mass of 340,000 kg each.