An international team of planetologists has discovered the first evidence that the geyser emissions of Enceladus and the subglacial ocean of this world contain giant amounts of phosphates. Their concentrations are hundreds of times greater than the fraction of these phosphorus compounds in Earth’s oceans. This discovery confirmed recent theoretical predictions of astronomers about the presence of large amounts of phosphorus on Enceladus.
Enceladus is a unique satellite of Saturn. There is a subglacial ocean in its interior, which periodically generates the most powerful geyser emissions in the vicinity of the planet’s south pole. Scientists have been debating for years whether the waters of Enceladus contain critical elements for life, including phosphorus, which is necessary for the synthesis of DNA and RNA molecules, as well as fats.
Astronomers recently discovered evidence that phosphorus compounds must be present in Enceladus’ ocean in large quantities. This prompted a team of planetologists led by Frank Postberg, a professor at the Free University of Berlin, to begin looking for traces of these potential “building blocks of life” in data collected by the CDA instrument aboard Cassini as the probe flew through the geyser emissions of Enceladus.
Enceladus’ phosphorous riches
The device, designed to study the properties of cosmic dust, hit some ice crystals from Enceladus’ frozen ocean. Scientists used it to study the chemical composition of the ice and look for possible phosphorus compounds in the interior of Saturn’s moon. To do this, the researchers performed spectral analysis of these ice crystals.
They found many molecules of sodium phosphate. The discovery not only confirmed the predictions of the theorists, but also revealed a geochemical cycle that explains the presence of soluble phosphorus compounds in the waters of Enceladus.
The authors of the work believe that the subglacial ocean of this Saturn’s satellite has an alkaline environment, with a large number of carbonic acid ions, but it contains almost no calcium ions. This contributes to the formation of calcium carbonate, and also prevents the deposition of phosphorus in the form of insoluble apatite from calcium phosphate.
The possibility of life on Enceladus
Similar conditions, as many geologists now speculate, existed in lakes on early Earth. Presumably it was in them that the first complex biological molecules formed and the first cells arose.
This similarity further increases the likelihood that extraterrestrial life may be lurking in the bowels of Saturn’s moon, the researchers believe, but note that excessive amounts of phosphorus can prevent its emergence.
Research planetary scientists have shown that Enceladus contains huge amounts of phosphate, which could be a key element for the emergence of life on this satellite of Saturn. The subglacial ocean of Enceladus has developed an alkaline environment that promotes the formation of calcium carbonate and prevents the deposition of phosphorus as insoluble apatite from calcium phosphate. This similarity to conditions on early Earth raises the possibility that extraterrestrial life may be lurking on Enceladus. However, excessive amounts of phosphorus may inhibit its occurrence.
