Enceladus as viewed from NASA's Cassini spacecraft. Photo Credit: NASAWashington, Aug.18 (ANI): Scientists involved in a new research relating to one of Saturn's moon, Enceladus, have opined that it has a warm and shifting interior similar to Earth.
According to Gustavo Gioia of the University of Illinois at Urbana-Champaign, one of the co-authors of this study, the new research on the moon's geologic features suggests water need not be involved, and life may very well exist on ice.
Gioia and his fellow researchers believe that the icy pole boasts ridges, vents, and other formations that emit geysers.
Geysers form when heat from deep inside melts water ice just below the surface, forming shallow pockets of liquid water. When tectonic movements crack the ice cap, liquid water bursts forth and quickly refreezes, creating the geysers. Gioia’s model "shows that it's possible to put these three observational elements"—geysers, geologic features, and heat flow—"into one unified explanation without the need for water."
He and colleagues claim the ridges where the plumes emerge were formed from a single heating event that expanded and cracked the surface. A shell made of icy compounds is exposed by the ridges, causing the compounds to decompress and absorb heat. The compounds then explosively split into smaller parts and send ice crystals and gases skyward, they add. "That doesn't mean that there is no [liquid] water. It just means that you can explain the whole thing without there being water there," Gioia says. The moon has since been dubbed a cosmic graffiti artist, because the huge geysers spew icy particles and vapor that cover its surface.
Last year study co-author Susan Kieffer, also at the University of Illinois, suggested that the gases in the plume are produced from stiff compounds called clathrates that form a shell under the South Pole's cap.
Clathrates are like icy lock boxes—outer shells of water ice are bonded to gases such as methane or carbon dioxide that are trapped inside. When periodic tectonic cracks appear in the ice above, the clathrates may decompose explosively and send gassy plumes skyward.
Scientists say that gases from deep inside the moon may continue to rush upward, carrying the heat that breaks down the clathrates. This process, known as heat advection, doesn't require the surface temperature to be very different from the temperature where the gases originate.
The research appears in the online edition of the Proceedings of the National Academy of Sciences of August 15.
David Stevenson, a planetary scientist at the California Institute of Technology in Pasadena, and Carolyn Porco, a senior research scientist at the Space Science Institute in Boulder, Colorado, believe that the heat source and the liquid water lie beneath the Moon’s surface. (ANI)