Uranus’s tiny moon Ariel may have had a subsurface ocean that made up around 55% of its total volume. By mapping craters, crags, and ridges on the moon’s surface, planetary scientists modeled how thick Ariel’s crust was before it…

Uranus’s tiny moon Ariel may have had a subsurface ocean that made up around 55% of its total volume. By mapping craters, crags, and ridges on the moon’s surface, planetary scientists modeled how thick Ariel’s crust was before it…