Enceladus
Enceladus is the sixth-largest moon of Saturn and the 18th largest in the Solar System. About 500 kilometres (310 miles) in diameter, it is covered by clean snow hundreds of meters thick, making it extremely reflective and cold. What makes Enceladus scientifically significant is its remarkable geological activity. The Cassini spacecraft discovered water-rich plumes shooting from the south polar region in 2005, revealing cryovolcanic geysers that eject about 200 kilograms (440 pounds) of material per second into space. More importantly, in 2014 NASA confirmed that Enceladus harbors a large subsurface ocean of liquid water beneath its ice shell. Because this ocean may contain conditions suitable for life, including hydrothermal activity and chemical energy sources, Enceladus has become a prime target in the search for life beyond Earth.
Sources
- en.wikipedia.org: “Enceladus is the sixth-largest moon of Saturn and the 18th largest in the Solar System. It is about 500 kilometres (310 miles) in diameter”
- en.wikipedia.org: “It is covered by clean, freshly deposited snow hundreds of meters thick, making it one of the most reflective bodies of the Solar System.”
- en.wikipedia.org: “In 2005, the spacecraft Cassini started multiple close flybys of Enceladus, revealing its surface and environment in greater detail. In particular, Cassini discovered water-rich plumes venting from the south polar region. Cryovolcanoes near the south pole shoot geyser-like jets of water vapour, molecular hydrogen, other volatiles, and solid material, including sodium chloride crystals and ice particles, into space, totalling about 200 kilograms (440 pounds) per second.”
- en.wikipedia.org: “In 2014, NASA reported that Cassini had found evidence for a large south polar subsurface ocean of liquid water with a thickness of around 10 km (6 mi).”
- en.wikipedia.org: “Still-ongoing research suggests that Enceladus's hydrothermal environment could be habitable to some of Earth's hydrothermal vent microorganisms”