Moons

The Pluto system (Image NASA/STScI/Showalter)

An article just published in the journal “Nature” describes a research on Pluto and its moons showing how two of them, Nix and Hydra, spin in an uncontrolled and unpredictable way. This study is based on an analysis of the observations made using the Hubble Space Telescope but because of the considerable distance they’re far from complete. For this reason, it’s possible that the two other small moons of Pluto, Styx and Kerberos, are in the same situation.

Artistic concept of the space probe that will study Europa and its trajectory in the Jupiter's system (Image NASA/JPL-Caltech)

NASA announced the nine instruments selected for the space probe that will explore Europa, a large Jupiter’s moon. The interest in a mission of this type has grown over the years, since the Galileo space probe found evidence of the existence of Europa’s subsurface ocean. The new mission will try to determine whether that ocean contains life forms.

Hubble Space Telescope images of Ganymede's aurorae colored blue overlaid on a Galileo space probe image of the moon (Image NASA/ESA)

The Hubble Space Telescope has been used to study Ganymede, the largest Jupiter’s moon, and in particular its aurorae. Analyzing their characteristics, it was possible to get the best clues found so far of the existence of a Ganymede underground ocean of liquid salt water. This ocean may contain more water than it exists on the surface of the Earth.

Artistic cutaway of Saturn's moon Enceladus that shows hydrothermal activity (Image NASA/JPL)

An article just published in the journal “Nature” shows a research based on the detections carried out by NASA’s Cassini space probe. Among other information provided by the mission there’s also evidence that on Enceladus, one of Saturn’s moons, there are signs of the presence of hydrothermal vents. This means that there are waters heated by geothermal energy similar to those existing on Earth, where the presence of various microorganisms abounds, particularly those known as extremophiles.

A comparison of the map of Ligeia Mare on Titan before and after the application of despeckling (Image NASA/JPL-Caltech/ASI)

Since July 2014, NASA’s space probe Cassini has been accomplishing its mission exploring Saturn and its moons, including Titan. Its SAR (Synthetic Aperture Radar) instrument allowed to map almost half of the surface of this satellite, allowing to know its geological features like never before. Now these surveys can offer even more details thanks to a new technique that improves their quality.

The images created thanks to the Cassini space probe’s SAR are “grainy”, like photographs of limited quality. Scientists must strive to interpret the smaller geological features or to identify changes in images of the same area taken at different times. The new technique called despeckling by its developers is improving the situation.