Lack of craters on the surface
- surface is 10 MY or younger?
- Analysis of the cracks implies a layer of brittle ice, less than 1 km thick above the supposed ocean
- Lots of pits, moats, and domes
- these are holes that were formed locally where the ice has collapsed due to internal geologic activity.
- that activity may be subsurface convection
- if convection is determined to be the process creating the pits, moats, and domes, then the possibility of a water ocean is more unlikely, or perhaps it exists at lower depths
- the speed at which the convecting ice might move is difficult to determine from the flyby pictures
- water has reached surface to form once-again-frozen "ponds"
- there are many examples of "puddle-like" flow
- Magnetometer detected near surface currents
implies the presence of convecting/circulating currents in a salty ocean
- what is needed to form a magnetic field?
- electric currents, => electrically conducting material in motion
- electrically conducting materials include:
- iron (iron core of a planet)
- salt water
- implies the presence of convecting/circulating currents in a salty ocean
To read more this subject, you may leave the tour and read our section on the recent findings about this moon, or take the Exploratour on the question Does Europa have an Ocean?
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