Last weekend, NASA’s Cassini spacecraft made its final flyby of Saturn’s moon Enceladus, a 310-mile wide (500 km) ice ball that has sparked the interest of many scientists.
Data collected by Cassini confirmed a global subsurface ocean on the tiny moon, which made scientists think of the possibility of microbial life on other similar moons that are far from a sun (of any planetary system).
Curt Niebur, a program scientist in the Devision of Planetary Sciences at the National Aeronautics and Space Administration (NASA) Headquarters in Washington, said that before the data from Cassini, had people suggested the existence of a global ocean underneath Enceladus’ icy surface, they would have been laughed at. That is how surprising the discovery was; almost no one was expecting it.
In hopes of finding extraterrestrial life, scientists are now also looking at moons orbiting extra solar planets. If Enceladus is an indication of the possibility of life forms, then the number of habitable moons could in fact be larger than that of habitable planets, according to some scientists.
On its final flyby, Cassini was within 3,106 miles (4,998 km) from the south polar region of Enceladus.
Ever since November 1980 and August 1981 – when Voyager 1 and Voyager 2 made their flybys of Saturn – scientists have been mesmerized by the tiny moon Enceladus. The moon was embedded into Saturn’s E ring.
The data from Cassini shows that large portions of the moon’s ice surface are in fact geologically young. In February 2005, the Cassini spacecraft also discovered fissures on Enceladus’ southern polar region, through which some sort of material was being ejected. Temperatures in that area were a lot higher than expected, according to scientists.
It appears as though the plumes contain organic compounds. Based on the measurements from Cassini, the core of Enceladus is rocky. The subsurface ocean that was initially thought to be regional, also turned out to be global
Further analyses of the plumes along with chemical modelling on the subsurface ocean suggest that the water is salty and not too alkaline or too acidic to support life.
Hydrothermal activity may also be occurring where the core meets the ocean, which could suggest that there is a source of energy and nutrients that could mimic conditions of hydrothermal vents on our planet’s ocean floor – and therefore imply the existence of life.
Image Source: solarsystem.nasa