NASA Cassini spacecraft: NASA’s Cassini spacecraft has produced new composite images of Enceladus, Saturn’s moon, and these images are the most detailed global infrared views that have ever been produced. The data that the images have been built on gives strong evidence to prove that ice from Enceladus’ interior has resurfaced in the moon’s northern hemisphere, according to a statement by Caltech’s Jet Propulsion Laboratory, which manages the mission on behalf of NASA.
The Visible and Infrared Mapping Spectrometer (VIMS) of Cassini collected the light that Saturn, its rings and its 10 major icy moons reflected. This included infrared light as well as the light that is visible to humans. After that, VIMS got to work on separating the light into various wavelengths. This information cues scientists into the material that is reflecting the light. Data from VIMS, along with the detailed images that Cassini’s Imaging Science Subsystem captured, helped scientists in creating the new global spectral map of Enceladus.
Enceladus looks like a bright white snowball to the naked eye, seeming highly reflective. In 2005, Cassini scientists had found that Saturn’s moon was shooting out ice grains and vapour in huge plumes, and these were originating from an ocean that was under the icy crust of Enceladus. The newly created spectral map now shows that there is a clear correlation between the infrared signals and this geologic activity, which can be seen easily at the moon’s south pole. The south pole is where the moon’s “tiger stripe” gashes are present, and this is where the blast of ice and vapour from the interior ocean takes place.
However, what’s more is that the same infrared features also seem to appear in the northern hemisphere of the moon. According to scientists, this indicates that the northern area has a covering of fresh ice, but apart from that, the same kind of geologic activity, i.e., resurfacing of the land, has occurred in both the hemispheres. The statement said that the northern resurfacing could have been caused either by icy jets or by a more gradual movement of the ice through the crust’s fractures, causing it to emerge from the subsurface ocean to the surface.
The new research has been published in Icarus. The statement quoted VIMS scientists and research co-author Gabriel Tobie as saying that the infrared shows that the south pole’s surface is young, which was not very surprising since they were already aware of the jet blasting icy material.
Tobie added that now, due to these infrared eyes, the scientists would be able to go back in time and say that a large region in the north also appeared to be young and was active not very long ago, if seen in geologic timelines.
Cassini orbiter had been tasked with observing Saturn and it continued its task for 13 years before its fuel supply was exhausted. It was then plunged into the atmosphere of the ringed planet by the mission, so as to not cause any harm to Enceladus, which has the potential to have conditions suitable for life.