Our picture of habitability on Europa is changing

Prett good article actually, even if it has a somewhat slow start.
TL;DR: We all already knew that bacteria or other microorganisms potentially living in Europa’s sub-surface oceans likely have to inhibit hot spots at the ocean floor to survive, similar to bacteria living in the deep oceans on earth. Different simulations of Europa’s geology however suggest, that these hot spots may be less likely or indeed impossible to form on Europa’s ocean floor, at least in its current orbit and neighbouring moon cluster: the moon’s mantle may be too thick to be sufficiently geologically active to allow molten rock to penetrate to the ocen floor. It is hypothesised that this may have been possible in the past and may be possible in the future again, depending on the actual composition of Europa’s mantle and changes in its orbit.