NASA has posted the first raw images from the Cassini spacecraft passing in October 2015, to 45 km. only the surface of the south polar region of Enceladus, a moon of Saturn.
It was 10 years ago, the probe had allowed the discovery of a cryovolcanic activity on this satellite. This time, the overview runs a dive in the icy plumes of aerosols coming from fractures of the south polar region.
This is an opportunity to more accurately determine the chemical composition of the plumes and their origin ... fissure eruptions or emissions of several cryovolcanic fountains.
The low density of the plumes did not disrupt the path of the spacecraft.
Cassini was launched in 1997, with the Huygens probe of ESA. While Huygens studied the moon Titan, Cassini's instruments were sending information about the Saturn system, since his arrival in 2004.
Enceladus is a celestial objects among the brightest in our solar system, covered with ice reflecting 100% the sunlight, which explains the low surface temperature: about minus 201 ° C.
The scientific interest in Enceladus comes from the iced plume issued by this moon of Saturn, and the discovery of organic complexes in this aerosol. The tides have helped to maintain some heat, and hot spots associated with fountains were highlighted. Enceladus could have a place in the evolution of primitive sources of life, with the presence of heat, organic molecules and potentially liquid water.
The surface of Enceladus shows no craters size greater than 35 km. to the North ; other areas to the south, without crater, show a recent surfacing geologically: fissures, plains, corrugated terrain and other crustal deformations succeed. The surface of this moon of Saturn is supposed to be geologically "young", going back 100 million years, with an interior that may be present in the liquid state.
The surface of Enceladus - Craters to the north (top left), fractures to the south (center and right) - Doc. NASA JPL Caltech
Enceladus - close-up on the surface of an area south of the satellite - Doc. NASA JPL Caltech 10/28/2015
Cassini continues to transmit its data ... his next and final crossing near Enceladus will be held on December 19, at an altitude of 4999 km. this time, during which it will measure the internal heat flow.
The scientific challenges are to determine the characteristics and the geologic history of the moon, the physical process of creating its surface, analysis of the composition and distribution of surface materials, composition and internal structure of Enceladus and the interactions between the moon and Saturn's magnetosphere and its ring system.
Results are expected.
Enceladus and the edge of Saturn's rings, seen by the Cassini probe that moves away. - Photo taken from 171,000 km - Doc. NASA JPL Caltech 10/28/2015
Cassini solstice mission - link
The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.