That Enceladus is one of the most spectacular moons in the Solar System is already known – for many reasons, including pure aesthetic ones. The frozen moon with its ice plumes and crater-ridden surface is a familiar pretty view, especially in the great imagery sent over by Cassini-Huygens in its periodic flybys around Saturn since 2004.
The latest one was performed on October 28, and it was the deepest-ever dive of Cassini through the plumes – passing at just 30 miles above the Enceladus’ south polar region and with the objective of sampling the chemistry of the moon’s ocean.
The interest for the plumes is evident – the moon contains an ocean under its surface and has a hydrothermal activity, i.e. all the required ingredients to support bacterial life.
As reported in NASA’s press release, “the flyby will help solve the mystery of whether the plume is composed of column-like, individual jets, or sinuous, icy curtain eruptions — or a combination of both. The answer would make clearer how material is getting to the surface from the ocean below. Researchers are not sure how much icy material the plumes are actually spraying into space. The amount of activity has major implications for how long Enceladus might have been active.”
There’s still one final flyby Cassini has to perform on Enceladus, and it will take place on Dec. 19, 2015. At that moment, at an altitude of 3,106 miles, the tiny spacecraft will measure the amount of heat coming from the moon’s interior. A simulation of the flyby can be found here.