NASA’s Cassini spacecraft successfully completed its Oct. the 1st flyby of Saturn’s moon Enceladus and its jets of water vapor and ice. At its closest approach, the spacecraft flew approximately 62 miles (100 kilometers) above the moon’s surface. The close approach was designed to give some of Cassini’s instruments, including the ion and neutral mass spectrometer, the chance to “taste” the jets themselves.
The images of the surface include previously seen leading-hemisphere terrain. However, during this encounter, multi-spectral imaging of these terrains extended farther into the ultraviolet region of the electromagnetic spectrum than had previously been achieved at this resolution. By looking at the surface at ultraviolet wavelengths, scientists can better detect the difference between surface materials and shadows than they can at visible wavelengths, where icy materials are highly reflective and shadows are washed out. With both ultraviolet and visible images of the same terrain available to them, scientists will better understand how the surface coverage of icy particles coming from the vents and plumes changes with terrain type and age.
Enceladus. In this picture it is visible the southern regions of the satellite (35 degrees south latitude, 45 degrees west longitude). Enceladus is one of the most geologically active satellites in the Solar System. Scientists suggest the existence of liquid water ocean under the ice, peppered with cracks and faults of satellite bark. In this picture received on September 13, 2011, Enceladus appeared from a distance of only 42000 km.
Moons of Saturn. Enceladus and Tethys, two rather large satellite of Saturn, were in the field of view of the cameras, “Cassini” September 13, 2011. Satellite Tethys is seen at the bottom of the picture. It seems that Tethys is in the foreground. This is indeed the case: when the shooting distance to Tethys was 208 000 km and Enceladus – 272000 km. Tethys is also twice the size of Enceladus, 1,062 km against 504. Saturn’s rings create, as always, unique atmosphere.
Hyperion. On September 16 probe “Cassini” flew past one of the strangest moons of Saturn, Hyperion. The surface of this small (only 270 km in diameter) satellite is like a sponge. Another feature of Hyperion is its random rotation around its own axis. Due to this it is difficult to predict in advance which part of the satellite turns to the cameras, “Cassini” during their next encounter.