It’s less wide than the United Kingdom, but Enceladus is of outsized interest to astrobiologists because of its subsurface ocean, which lies beneath its icy crust.

Source: https://gizmodo.com/saturn-moon-enceladus-phosphorus-key-life-ingredient-1850543604

These moons are of great interest to both planetary scientists and astrobiologists, as they feature dynamic surfaces and possibly warm liquid oceans tucked beneath their icy surfaces.

Source: https://gizmodo.com/big-upcoming-deep-space-missions-nasa-esa-russia-1850164273