Even on smaller icy moons, the chances for life on the ocean floor are good

The fact that astrobiologists have such high hopes for icy moons like Enceladus or Europa is not only due to the oceans they have been able to detect under their ice crusts, but also to the fact that they are geologically active worlds. The culprits are the giant parent planets Saturn and Jupiter, respectively, which really knead the moons with their gravitational force. This creates heat, which keeps the water in their hidden oceans liquid and relatively warm. The water in turn dissolves from t...