Readers discuss Mimas’ hidden ocean and ancient cave art

Hidden depths

Slight changes in the orbit of Saturn’s moon Mimas hint at the presence of a vast, young ocean beneath the satellite’s icy surface that may have formed between 5 million and 50 million years ago, Adam Mann reported in “This Saturn moon may harbor water” (SN: 3/9/24, p. 8).

Reader Bobby Baum asked how the ocean formed so recently and whether an ocean could have formed multiple times in the past.

Saturn’s moons gravitationally interact with one another and with their ringed parent planet as they orbit. This complex dance causes tidal stresses on the moons, generating heat that can melt a satellite’s icy interior.