When we think of moons, we generally imagine barren and lifeless lands. However, there are many moons in our galaxy, some of them are bound to be otherwise.
Normal viewing of Saturn’s moons would also produce a similar feeling – plain. However, some experiment with wavelength and taking nice pictures with expensive space equipment will make the moon looks a lot more interesting.
NASA released a set of new sunset images of Enceladus, one of Saturn’s moons. It has a glistening ice wall, almost white, making it appear like a giant space-snowball, reported the ScienceAlert.
Then, the astronomers viewed the moon in the infrared wavelength. Infrared light is the light beyond the visible spectrum of human eyes and can be viewed with specialised gear. The new discovery based on these infrared images suggests that the ice is fresh, leading the scientists to believe that there might be some activity going on around the moon’s surface.
The Cassini spacecraft mission ended in 2017. The database collected by Cassini's Visual and Infrared Mapping Spectrometer (VIMS) was reanalysed recently and these infrared images came out as a result.
It was always known that there is some activity on the moon. “Plumes of salty water” were discovered in 2005 by Cassini. The water seemed to be spouting out of four fairly large chasm’s around Enceladus’s South Pole. These fractures were named as Tiger Stripes.
With Cassini’s help, researchers were able to map more than a hundred geysers within these fractures.
Researchers believe they are a result of the moon’s tidal forces (due to friction between Saturn and Enceladus’s gravity). Tidal force is present between all planets and their moons; that is how our moon affects waves on Earth.
Researchers believe as Saturn pulls and stretches Enceladus, internal heating and geothermal activities within the moon rises. As a result, cracks occur on the ice surface. As warm water spouts out of these cracks, it freezes over the surface, giving rise to a fresh layer of ice.
The ice study suggests that it is crystalline (like Earth’s ice) and not amorphous (almost every other space ice). This concludes that there has been active geothermal water heating across the moon’s surface, as images from North pole also reveal a fresh layer of crystalline ice (without the presence of tiger stripes to explain the presence). It can indicate sea activity of up to millions of years old.
You can access the interactive images here.