Europa's Hidden Ocean Has Twice As Much Water As All of Earth's Oceans

Beneath an ice shell about 15–25 km thick, Jupiter's moon Europa harbors a global ocean of liquid salt water — kept warm by tidal heating from Jupiter's gravity. Estimates suggest this hidden ocean may hold two to three times the total volume of water on Earth's surface.

Why It Could Host Life

Europa has the basic ingredients for life as we know it:

• Liquid water — the most fundamental requirement
• Energy: tidal heating + chemical reactions at hydrothermal vents
• Organic chemistry: Carbon, nitrogen, sulfur, and other elements
• A stable environment: The ocean has likely existed for billions of years

The Plumes

The Hubble Space Telescope and Galileo probe both detected evidence of water plumes erupting from Europa's surface — meaning water from the hidden ocean reaches space. Future missions could fly through these plumes and sample the ocean without ever landing.

NASA's Europa Clipper

Launched in 2024, NASA's Europa Clipper will perform 49 flybys to map Europa's surface, measure ice thickness, search for plumes, and assess habitability. It is the largest interplanetary mission NASA has ever flown — and it might tell us, by the 2030s, whether we are alone.