Europa (Jupiter)
Position on the route: 12/45 · level needed 80 · journey (Mk0 engine) 16.4 h
By the numbers
| Distance from Jupiter | 671,000 km |
|---|---|
| Diameter | 3,122 km |
| Gravity | 1.31 m/s² (0.13 g) |
| Day = year | 3.55 days (tidally locked) |
| Surface temperature | −160 °C |
| Ice shell | 15–25 km |
| Ocean | 60–150 km deep |
| Radiation | 5.4 Sv a day (lethal) |
The story
A smooth shell of ice; beneath it more than twice the liquid water of all Earth’s oceans. Jupiter’s tides knead Europa and heat its interior; hydrothermal vents may line the ocean floor, the conditions of Earth’s deep-sea life. It is one of the most hopeful places in the solar system to look for life.
The reddish streaks on the shell are salts and sulphur; Hubble and Galileo data pointed to plumes of water. The problem is radiation: Jupiter’s magnetic field bombards the surface with several sieverts a day, a lethal dose for an unprotected person within a day. Bases are dug a few metres under the ice.
Galileo (1995–2003) revealed the ocean through magnetic measurements; Juno passed 352 km above it in 2022. Europa Clipper launched in 2024 and will make 49 flybys from 2030; ESA’s JUICE visits Europa twice on its way to Ganymede.
Missions
- Voyager 2 (1979): first detailed images
- Galileo (1995–2003): evidence of the subsurface ocean
- Juno (2022): 352 km flyby
- Europa Clipper (2024–2030), JUICE (2023–2031)
Colony note
Plenty of water, low gravity; but radiation puts the base under the ice. In the game it needs no shield: the shell protects.
What probes bring back
- Ice shell 15–25 km, a salty ocean 60–150 km deep beneath (magnetic induction).
- Surface radiation 5.4 Sv a day: lethal to a human.
- Water plumes measured; an ocean sample can be taken from orbit.