The small ice moon Enceladus is much more active at the South Pole than can be calculated. What's going on on this distant satellite of Saturn?
Enceladus: Not for sun lovers
Enceladus is an extremely cold ice ball about three hundred kilometers in diameter. Maximum temperature in the height of summer: two hundred degrees below zero. Gravity is almost microscopic low. Because the moon consists largely of ice - and presumably contains a lot of water under the thick ice cap - researchers consider Enceladus an interesting candidate for extraterrestrial life. The Antarctic contains a number of puzzling lines, where geysers spray liquid water into space.
Measurements from the infrared meter of satellite Cassini show that much more heat is released in the Antarctic than predicted by calculations: 15.8 billion watts, 20 times as much as all the hot springs in Yellowstone National Park (in fact, the crater of a dormant giant volcano ) produce or two-thirds of the capacity of all power plants in the Netherlands together. Saturn (and therefore also Enceladus) is very far from the sun: the sun on Saturn has only one percent of the power here on earth. Based on these measurements, even the biggest skeptics are now convinced that an ocean of liquid water really does exist in Enceladus.
Mysterious heat source
In short: something must cause this extremely large heat production. Tidal effects are excluded, they deliver no more than one and a half billion watts. Radioactive decay (the driving force of volcanoes and geothermal energy on Earth) up to 0.3 billion watts. Researchers don't believe in a zero-point alien power plant, but now think Enceladus has a complicated trine relationship with neighboring moon Dione and Saturn. Complicated gravitational interactions between these three celestial bodies, through which Enceladus is regularly molded, would explain the current strong activity and alternate with longer periods of inactivity. It would be a coincidence that we just encountered Enceladus in an active phase.
Cassini's measurements of the water plumes that Enceladus emits showed that they contain many dissolved salts and organic matter. Some exobiologists therefore want a satellite to take samples of such a plume to find out if Enceladus contains extraterrestrial life. Dig deep, like on Jupiter's icy moon Europe is not necessary.