Enceladus, one of the moons of Saturn. An apparently insignificant ice ball until, thanks to the Cassini probe, it was possible to study this world more closely. And suddenly, a remote world of 500 km in diameter, has become one of the most promising places to find life or, at least, the precursors of it.
Enceladus is a seemingly cold and inhospitable world, but it hides a surprise beneath the frozen surface: an ocean of liquid water, in a region of the solar system where there could not be. Moreover, from the cracks on the surface, powerful geysers emit water vapor, salts and ice that feed one of the rings of Saturn. The most reliable theories claim that the underground ocean of Enceladus is kept liquid thanks to the geothermal vents, which would remain active thanks to the tidal forces induced by the gravitational field of Saturn.
So it may be that, billions of miles away, under a thick crust of ice, life may have developed?
Answering this question would require a direct visit to the site, as nothing intelligent certainly lies in the ocean of Enceladus. What we can do, from here, or with the probes, is to observe the traces of the chemical elements present in search of possible organic molecules that can be the result of biological processes.
And that’s what Frank Postberg and Nozair Khawaja of Heidelberg University in Germany found. Scientists, using data from the Cassini probe, in particular from the Cosmic Dust Analyzer (CDA) and the Ion and Neutral Mass Spectrometer (INMS), have identified the presence of complex organic molecules, composed by hundreds of carbon atoms and from other elements like hydrogen, oxygen and maybe nitrogen.
The proposed theory is that, like what happens in the hydrothermal vents in the depths of the Earth‘s oceans, complex organic molecules would remain trapped inside gas bubbles that, arriving at the surface, would disperse their precious content.
But in a nutshell, did we find life? Not yet. But today we know that complex organic molecules can form even in the most mysterious or extreme places. On Enceladus, well beyond the frost line, a protected environment, with a source of energy and the right ingredients, has led to the creation of complex organic molecules. At this point, a dedicated mission to Enceladus is almost obligatory, if anything else any discoveries would allow us to understand a little better what happened here on Earth, billions of years ago.
About the discovery, as Frank Postberg commented:
If we could visit Enceladus again, we would bring instruments that could see the whole molecule, not just these fragments, and this would tell us exactly what they are and how they were created.
These were the words of Nozair Khawaja:
It seems that this mysterious moon will keep the secret still for some time, but it is within reach of a future mission for Enceladus to solve this part of the puzzle.