Scientists find new evidence of habitability on Saturn's moon Enceladus
Saturn's moon Enceladus has a greater chance of habitability as its ocean may be rich in dissolved phosphorus, an important life element but previously undetected in this planet of the solar system, a new study suggests.
Enceladus, the second moon discovered around Saturn, has a thick ice shell in a subglacial ocean, forming a plume where scientists have found five basic elements of life: carbon, hydrogen, nitrogen, oxygen and sulphur. However, the essential element phosphorus has not yet been found.
Due to the absence of phosphorus, which is an indispensable component of bones, cell membranes and DNA in humans and animals, Enceladus was once considered uninhabitable by the international scientific community.
A team of international researchers led by Chinese scientists, has, however, contradicted the previous findings by claiming to have discovered phosphorus in the form of phosphates in the moon's ocean.
In the study, the researchers created a seawater-rock interaction model to simulate the geochemistry of Enceladus' rocky ocean floor.
"The ocean water on the planet was found to be highly alkaline (very salty) and devoid of oxygen, similar to soda water people drink on Earth," said lead researcher Hao Jihua, from the University of Science and Technology of China.
In such a "soda" environment, it would take about 100,000 years for phosphorus to dissolve from Enceladus' rocks into the ocean.
Hao noted that an ocean of liquid water might have existed for more than 100 million years in Enceladus. Given this potentially long history, the rocks of the planet can be expected to release considerable amounts of phosphorus into the ocean.
The study was published in the peer-reviewed journal Proceedings of the National Academy of Sciences of the United States of America.
Although phosphorus has not yet been explicitly found, this study gives a scientific reference for the future exploration of potential life on Saturn's moon Enceladus, according to the researchers.