The ocean of Enceladus, Saturn's icy moon, may be hiding another vital ingredient of life: phosphorus.
In fact, thanks to the data collected by the Cassini-Huygens mission, a joint interplanetary robotic mission of NASA, the European Space Agency (ESA) and the Italian Space Agency (ASI) launched in 1997, a group of researchers led by the University of Science and Technology of China estimated the formation and abundance of this element in the ocean of Enceladus: according to the study, published in the journal of the US National Academy of Sciences (PNAS), phosphorus is found in concentrations similar to or even higher than those present in the terrestrial oceans.
Phosphorus and its compounds are involved in the fundamental functions of all known life forms: molecules containing phosphorus, for example, are part of DNA, RNA (the single-stranded structure involved in various roles of decoding and expression of genes) and of the molecule called Atp, which provides energy in many metabolic reactions.
Observations by the Cassini spacecraft have already led to the discovery of many 'building blocks' of life within the geysers of ice and water vapor that emerge from the ocean of salt water.
However, phosphorus was not among them: for this reason the researchers led by Jihua Hao built models based on the probe's data, to estimate the presence or absence of this element.
The results indicate that in particular orthophosphate, an electrically charged form of phosphorus that is involved in many biological reactions on Earth, would be found in abundance on Enceladus, in concentrations similar to or even higher than those of our planet's oceans.
