A new discovery has boosted the chances of life soon being found on another world. NASA has announced the detection of phosphorus, the rarest element that’s essential to life, in the oceans of Saturn’s moon Enceladus.
Six elements are essential for life as we know it to exist and function – carbon, hydrogen, oxygen, nitrogen, phosphorus and sulfur. Of those, phosphorus is by far the hardest to come by, so much so that scientists have suggested that its relative rarity in the cosmos could put a hard limit on how common extraterrestrial life may be.
But now, astronomers have for the first time detected phosphorus in one of the most promising places in our solar system for potentially finding life. Enceladus is a moon of Saturn that’s home to a global ocean of liquid water hiding beneath an icy shell, and previous studies have detected many ingredients vital for life there, as well as conditions like temperature and alkalinity that can be favorable to life.
The researchers examined data gathered by NASA’s Cassini probe, which investigated Saturn and its moon between 2004 and 2017. The ocean on Enceladus isn’t content with just sitting still – it’s known to burst through the moon’s icy crust in huge plumes of water that eject material into space, feeding Saturn’s E ring.
The team focused on ice particles the craft collected while zipping through the E ring, analyzing the composition of elements it found there. In doing so, the researchers discovered high concentrations of compounds called sodium phosphates, which are molecules of sodium, oxygen, hydrogen and phosphorus atoms.
Next, scientists in other labs conducted experiments to try to recreate the alien ocean that could produce these signatures, and found that phosphorus concentrations were at least 100 times higher on Enceladus than they would be in Earth’s oceans. Follow-up geochemical experiments showed that these concentrations would be possible through interactions either at a cold seafloor, or around hydrothermal vents, which are already suspected to exist on Enceladus.
“High phosphate concentrations are a result of interactions between carbonate-rich liquid water and rocky minerals on Enceladus’ ocean floor and may also occur on a number of other ocean worlds,” said Christopher Glein, co-investigator of the study. “This key ingredient could be abundant enough to potentially support life in Enceladus’ ocean; this is a stunning discovery for astrobiology.”
However, the researchers caution that finding the right ingredients for life doesn’t necessarily mean that life is present. After all, your kitchen might have all the ingredients needed for a cake, but they might not have come together in just the right way. Still, it’s an intriguing idea and detecting the hardest-to-find ingredient raises the chances ever so slightly in favor of aliens.
The research was published in the journal Nature.
Source: JPL