Europa

The hidden ocean

Vital statistics

• Mean radius: 1,561 kilometres
• Mass: 4.80 × 10²² kilograms
• Surface gravity: 1.31 metres per second squared
• Sidereal rotation: 3.6 days
• Orbital period: 3.55 days
• Mean temperature: -171 °C
• Axial tilt: 0.1 degrees

Field notes

• Beneath Europa's ice shell sloshes a salty liquid ocean that may hold twice as much water as all of Earth's oceans combined.
• Its surface is one of the smoothest in the solar system — a young, cracked ice skin, constantly resurfaced from below.
• It is a top candidate for life beyond Earth. NASA's Europa Clipper is on its way right now to find out if the ocean is habitable.

Data: NASA Planetary Fact Sheets. Explore the full interactive 3D map at the home page — every orbit is computed from real Keplerian elements.