A new study published this week in the journal Nature entitled "Macromolecular organic compounds from the depths of Enceladus" is revealing that Saturn's icy moon may hold the ingredients to life.
The research, acquired from the Cassini international space probe, indicates that the astronomical oceanic body contains complex organic material, in contrast to previous work that detected only simple compounds.
First proof of large organics
"This is the first evidence of large organic molecules from an extraterrestrial aquatic world. They can be generated only by equally complex chemical processes," said in a statement planetologist Assistant Professor Dr Frank Postberg, study director and researcher at the Institute for Earth Sciences at Heidelberg.
The newly-uncovered molecules have masses above 200 atomic mass units, far more than the previously known compounds of 50 atomic mass units. Surprisingly, however, they are not water-soluble since they are composed of complex mixtures of components with functional groups containing oxygen and possibly even nitrogen that have likely been transferred to the surface by the moon's huge icy jets.
"Gas bubbles probably transport the molecules to the surface, where they form an organic film," explained Nozair Khawaja, who directed the related laboratory experiments with organic substances. "It looks as if this is how Enceladus conveys very high concentrations of its organic inventory from the ocean's depths to the surface of the water. From there, it is launched into space together with ocean water droplets."
The discoveries were made through the use of two mass spectrometers onboard the Cassini spacecraft called the Cosmic Dust Analyzer (CDA) and the Ion and Neutral Mass Spectrometer (INMS). The advanced experimental tools conducted compositional in situ measurements from the ejected ice grains coming from the moon's plume and Saturn’s E ring.
The data, stemming from a subset of a dataset collected over 13 years, allowed the researchers to study the organic chemistry of Enceladus's unattainable ocean's depths. The work is still preliminary and more Enceladus missions will be required to determine whether the molecules originate from hydrothermal or even biogenic processes.
Hope for alien life
Regardless, their mere existence is enough for scientists to begin expressing excitement about the potential of life on this frozen aquatic rock considered one of the most promising candidates for alien inhabitation. "The discovery of macromolecular compounds originating from a moderately warm water environment will fuel interest worldwide in such icy moons as possible habitats for extraterrestrial life," said Prof. Dr Mario Trieloff from the Klaus Tschira Laboratory for Cosmochemistry at the Institute of Earth Sciences.
The Cassini-Huygens mission, a joint initiative of NASA, the ESA, and Italy's ASI space agency, first entered Saturn's orbit in 2004. It drew close to Enceladus in 2005 and has since revealed many outstanding facts about the unassuming moon.
The planetary rock has a large sub-surface ocean underneath its icy crust that scientists speculate houses powerful hydrothermal vents. Geysers have also been spotted that release water vapor and ice grains that end up on one of Saturn's rings revealing a complex relationship between the planet and its orbiting moon.