Size and Shape:
* Diameter: 3,122 km (1,939 mi)
* Mass: 4.8 × 10^22 kg (1.1 × 10^23 lb)
* Surface Area: 3.09 × 10^7 km² (1.19 × 10^7 mi²)
* Shape: Slightly oblate (flattened at the poles)
Composition:
* Surface: Primarily water ice, with trace amounts of other materials like salts, hydrated minerals, and organic molecules.
* Interior: Likely a rocky core with a possible metallic iron-nickel core.
* Between the core and the surface: A large subglacial ocean of liquid water, estimated to be twice the volume of all of Earth's oceans combined.
Surface Features:
* Craters: Relatively few craters, indicating a geologically active surface.
* Linear features: Long, dark streaks and ridges that may be caused by tectonic activity.
* Chaos regions: Areas of jumbled terrain, possibly created by volcanic eruptions or subglacial processes.
* Lenticulae: Dark, circular features with smooth surfaces, potentially volcanic features.
* Cryovolcanoes: Evidence suggests potential volcanic activity, but instead of spewing magma, they might release water vapor, ammonia, or other materials from the subsurface.
Orbit and Rotation:
* Orbital Period: 3.55 days
* Orbital Distance from Jupiter: 671,000 km (417,000 mi)
* Rotation Period: 3.55 days (synchronous with its orbit, meaning it always shows the same face to Jupiter)
Temperature:
* Average Surface Temperature: -171 °C (-274 °F)
* Internal Temperature: Potentially much warmer due to tidal heating caused by Jupiter's gravity.
Magnetic Field:
* Weak Magnetic Field: Europa has its own weak magnetic field, suggesting the presence of a conducting fluid in its interior, likely the salty subglacial ocean.
Atmospheric Pressure:
* Very Thin Atmosphere: A tenuous atmosphere composed mostly of oxygen, possibly produced by the breakdown of water ice by radiation.
Other Notable Features:
* Evidence of potential habitability: The presence of liquid water and organic molecules makes Europa a prime candidate for harboring life, making it a high-priority target for future exploration.
* High level of geological activity: Europa's surface and interior are likely dynamic, with ongoing tectonic and possibly volcanic activity.
It's important to note that these are just the key physical properties of Europa. There is still much we don't know about this fascinating moon, and further research is ongoing.
