MVP ARCHIVE NASA | Search for Life Phase 01-06: Enceladus / Saturn's Moon - Discovery of Water Vapor Plumes and Organic Molecules

Saturn's Moon - Discovery of Water Vapor Plumes and Organic Molecules

Despite being a small icy celestial body, Saturn's moon Enceladus is currently attracting attention as one of the places with the highest potential for life.

It is approximately 500 km in diameter, a moon far smaller than our own. However, this small world has brought about discoveries that have significantly changed our approach to astrobiology.

Discoveries by the Cassini Spacecraft

In 2005, NASA's Cassini spacecraft discovered massive water vapor plumes erupting from near the south pole of Enceladus.
It was confirmed that the plumes erupting from cracks in the ice into space contained not only water vapor but also ice particles, carbon dioxide, methane, ammonia, and organic molecules, which are the building blocks of life.

Furthermore, Cassini's observations revealed that the ejecta also contained molecular hydrogen, which is thought to be produced when water and rock react at high temperatures.
This strongly suggests the possibility of hydrothermal activity occurring on the seafloor inside Enceladus.

Ecosystems around deep-sea hydrothermal vents that do not require sunlight

On Earth, ecosystems that do not require sunlight exist around deep-sea hydrothermal vents.
If a similar environment exists on Enceladus, it may possess the three conditions considered necessary for life: liquid water, chemical energy, and organic molecules.

Future life exploration

What is particularly important is that on Enceladus, we can analyze substances being released into space as water vapor without having to directly drill into the internal ocean.
This makes it one of the few celestial bodies where we can indirectly investigate a subsurface ocean, which is a significant advantage for future life exploration.

To date, life itself has not been discovered.
However, the observational results left behind by Cassini have shown that Enceladus is not merely an icy moon, but a world that may possess an environment capable of supporting life.

Enceladus is the first celestial body where humanity has confirmed that the materials necessary for life are naturally being released into space.
As the front line of extraterrestrial life exploration, this small icy world continues to attract the attention of many researchers.