Enceladus's hot spot on the pole

The more we know about Enceladus, the more attractive seems this compact water world. This 500 kilometers moon of Saturn is one of the most geologically active bodies of the Solar System. Under ice surface lies great ocean supplying with liquid water powerful geysers, located in its suth polar region. Cassini spacecraft several times flied through their plumes and obtained data about chemical compositiont of water in this distant ocean. Besides, unlike another known water world, Europa, Enceladus's orbit does not pass through deadly radiation belts. This makes easier future crewed expedition on the surface. Liguid salty water, enriched with minerals can supply life. 

The last data, obtained by Cassini , show that ocean can be much closer to its surface, than it was thought before.

Image: NASA/JPL

New study of US- french researchers analyzes images of moon's south pole, taken by Cassini in microwave range.

They found that ice temperature at just several meters deep is 20 C higher than in other areas of the moon.

Image: Nature Astonomy

The images taken with resolution   ~50 m and ~200 m  in the cross- and along-track directions, show thermal anomaly. Researchers are convinced that this anomaly cannot be explained by solar heat accumulation as well as tidal forces from Saturn. There is some other energy source, which nature is still unknown. 

One more discovery is that ice crust in the south pole area is much thinner than in other Enceladus regions.  

Image: Nature Astonomy

According previous data, average thickness of ice crust is about 18 - 22 kilometers. However under south pole area it is only 2 - 5 kilometers thick.

Interesting, that in Earth's Pole area, in Antarctic, there is lake Vostok, hidden under 4 kilometers ice crust, but samples, taken from it haven't any life evidences.

 For further reading: http://www.nature.com/articles/s41550-017-0063