One of Saturn’s moons found to have all ingredients essential for life

Research finds ammonia and inorganic phosphorus in Enceladus’ ocean

Saturn’s moon Enceladus may have all the ingredients necessary to host life, according to a new study based on data from Nasa’s Cassini spacecraft mission.

The spacecraft ended its mission in 2017 but scientists are still pouring over the data it collected to understand more about Saturn and its moons.

Over the course of its mission, Cassini discovered geyser-like water plumes erupting through the icy shell of Saturn’s moon Enceladus, long thought to be a potential place in the Solar System outside of the Earth with conditions conducive for life.

The spacecraft performed a close flyby of Enceladus in 2008 during which its instruments analysed the plumes.

Water in the plumes has been found to contain a range of volatile molecules such as carbon dioxide, water vapor, and also traces of nitrogen, and some complex organic compounds.

A new yet-to-be peer-reviewed study, posed as a preprint in arXiv, has now discovered ammonia and inorganic phosphorus in Enceladus’ ocean.

Researchers, including those from Santa Fe Institute in the US, have theorised how these chemicals could make Enceladus conducive for the emergence of life.

The research builds on previously known ecological and metabolic theory which found that the ratio of carbon to nitrogen to phosphorus (C:N:P) was consistent across ocean biomass at 106:16:1.

This ratio points to a link between the chemistry of life living in the deep ocean and the ocean itself.

It is also seen as a signature to look out for in the detection of life in ET environments, especially in ocean worlds like Europa and Enceladus.

The latest study, according to scientists, offers a “powerful interpretative lens to assess whether extraterrestrial environments are compatible with living ecosystems.”

Data from various missions show that Enceladus has a high level of phosphate molecules in its ocean.

“These reports of phosphorus follow on the tails of previous work identifying numerous elemental constituents of terrestrial life (C, N, H, O) from the Enceladus plume,” researchers write in the new study.

Latest findings also hint that Enceladus’ ocean contains many chemicals commonly found in living organisms such as precursors to life-building blocks amino acids, as well as ammonium, and hydrocarbons.

In particular, research also suggests Enceladus may support life-signature chemical reactions producing methane molecules, a process called methanogenesis.

On Earth, methanogenesis is a signature of extreme microbial life forms called archaea that perform the reaction across a wide range of environments like hot springs and near deep underwater volcanic vents.

Now, new research suggests Earth’s methanogenic life forms may be compatible with Enceladus’ ocean.

With the discovery of phosphorus in high levels in the moon’s ocean, scientists say this “could be consistent” with something with a “small or metabolically slow biosphere, a biosphere with a recent origin of life.”

Scientists say their modeling points to “marginal compatibility” for life “with the ranges of dissolved N and P concentrations in the Enceledean ocean.”

The findings, according to researchers, can help finetune the approach to use ratios of chemicals as a tool for detecting life on other worlds.