Ocean Worlds Infographic

Editor's Note: Last update. April 19, 2017.

Earth isn’t the only ocean world in our solar system. Oceans could exist in diverse forms on moons and dwarf planets, offering clues in the quest to discover life beyond our home planet.

The worlds below represent the best known candidates in our search for life in the solar system – because where there is water, there is the potential for life. As you dive below, take note of each body’s ocean world status and its potential to sustain life as we know it.

Our home planet, Earth, is the only body known to have life. Called the “ocean planet,” Earth’s surface-land-to-water ratio is 29% land to 71% water.

Ocean World Status: Active – Dynamic ocean, known to support life

Scientists estimate that Ceres consists of about 25% water, a fraction of which could be in a liquid state. There are also clues that Ceres may have salty liquid below the surface and that it could have preserved an ocean deep underground. Data from NASA’s Dawn mission is continuing to provide new insights.

Ocean World Status: Possible – Evidence of an ocean, biological potential unknown

Scientists strongly suspect that a subsurface salty ocean lies beneath Europa’s icy crust. Tidal heating from its parent planet, Jupiter, maintains this ocean’s liquid state and could also create partially melted pockets, or lakes, throughout the moon’s outer shell.

Ocean World Status: Active? – Possibly a dynamic ocean, could support life

Ganymede is the largest moon in our solar system, and the only moon with its own magnetic field. Recent studies indicate a large, underground saltwater ocean is present at the Jovian moon. Ganymede could in fact have several layers of ice and water sandwiched between its crust and core.

Ocean World Status: Locked – Trapped ocean, unlikely to support life

Callisto’s cratered surface lies at the top of an ice layer, which is estimated to be about 60 miles (100 km) thick. An ocean, which is thought to be at least 6 miles (10 km) deep, could be directly beneath the ice.

Ocean World Status: Locked – Trapped ocean, unlikely to support life

Scientists predict that a regional resevoir about 6 miles (10 km) deep lies under a shell of ice 20 to 25 miles (30 to 40 km) thick at Enceladus’ south pole. This underground ocean is thought to feed the moon’s impressive jets, which spray from deep fissures (called “tiger stripes”) in the moon’s surface.

Ocean World Status: Active – Dynamic ocean, could support life

Titan is believed to have a salty subsurface ocean – as salty as the Dead Sea on Earth – beginning about 30 miles (50 km) below its ice shell. It is also possible that Titan’s ocean is thin and sandwiched between layers of ice, or is thick and extends all the way down to the moon’s rocky interior.

Ocean World Status: Locked? – May have a trapped ocean, unlikely to support life if ocean is trapped

Research suggests that Mimas has either a subsurface ocean or that its core is shaped like a football. If Mimas is hiding a liquid water ocean, it lies 15 to 20 miles (25 to 30 km) beneath the moon’s impact-battered surface.

Ocean World Status: Possible – Evidence of an ocean, biological potential unknown

Active geysers on Triton spew nitrogen gas, making this moon one of the known active worlds in the outer solar system. Volcanic features and fractures mark its cold, icy surface, likely results of past tidal heating. A subsurface ocean at Triton is considered possible, but is unconfirmed.

Ocean World Status: Possible – Evidence of an ocean, biological potential unknown

A world of many unknowns, Pluto could have rings and perhaps a subsurface ocean. Data from NASA’s New Horizons mission will provide new insights about this unexplored world.

Ocean World Status: Possible – Evidence of an ocean, biological potential unknow