14 DAY TRIAL // On Saturday, October 1, the NASA Cassini space probe completed its latest flyby of the Saturnine moon Enceladus. The mission was to focus the spacecraft's sensitive instruments on the geysers at the south pole of the celestial body, and observe as they are spewing out water particles and organic matter.
Previous investigations conducted in the Saturnine system have revealed that this object is responsible for contributing matter to the gas giant's E Ring, as well as water vapors to Saturn's upper atmosphere.
Naturally, mission controllers at the NASA Jet Propulsion Laboratory (JPL), in Pasadena, California, were interested in learning more about the tiger stripe features that adorn Enceladus' south polar regions. These structures are essentially cracks in the massive ice crust covering the object.
Through these cracks, massive plumes of water vapors, water-ice, and organic particles spew out of the hypothesized liquid ocean located under the miles-thick ice crust. The tantalizing possibility that Enceladus may have liquid water protected from solar radiation makes it a main target for astrobiology.
During the new flyby, Cassini flew only 100 kilometers (62 miles) above the surface of the Saturnine moon. The reason for flying this low was that the ion and neutral mass spectrometer instrument aboard the spacecraft had to be able to pass through the ejected plumes, collecting samples for analysis.
As the probe was approaching the moon, its high-resolution cameras were also able to capture several images of the geysers and tiger stripes themselves. Using a new observation technique, the JPL team was able to notice previously-unseen differences in material composition at these locations.
“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,” a JPL statement says.
“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,” the press release adds.
“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,” the document explains.
According to the flight plan, Cassini is scheduled to make another close pass near Enceladus on October 19. This time, the spacecraft will only come within 765 miles (1231 kilometers) of the Saturnine moon.