Liquid water is known to be present on Earth, covering 71% of its surface. Scientists believe liquid water is present in the Saturnian moons of Enceladus, as a 10-kilometre thick ocean approximately 30–40 kilometres below Enceladus' south polar surface, and Titan, as a subsurface layer, possibly mixed with ammonia.
Jupiter's moon Europa has surface characteristics which suggest a subsurface liquid water ocean.
Liquid water may also exist on Jupiter's moon Ganymede as a layer sandwiched between high pressure ice and rock.