CAPE CANAVERAL, Fla. — Scientists have discovered new organic compounds in icy geysers erupting from Saturn’s moon Enceladus, strengthening the case that the small ocean world could host conditions suitable for life.
The findings, published Wednesday in Nature Astronomy, are based on data collected in 2008 during NASA’s Cassini spacecraft’s close flyby of Enceladus. The moon, only 310 miles (500 kilometers) across, has long intrigued scientists because of its hidden subsurface ocean and powerful plumes of water vapor and ice particles streaming from cracks near its south pole.
“Being habitable and being inhabited are two very different things. We believe that Enceladus is habitable, but we do not know if life is indeed present,” said Fabian Klenner of the University of Washington, who co-authored the study.
An international team reanalyzed grains of ice captured by Cassini’s cosmic dust analyzer during its passage through Enceladus’ geysers. These newer grains struck the spacecraft at 40,000 mph (64,800 kph), allowing for clearer chemical readings than older particles previously found in Saturn’s outermost ring. While earlier studies had identified organics, questions remained about whether long exposure to space radiation had altered them.
The fresh analysis revealed familiar organic molecules, confirming their origin in Enceladus’ ocean, as well as newly identified chemical compounds. Scientists believe the moon’s rocky core and possible hydrothermal vents on its ocean floor may resemble environments on Earth where microbial life thrives.
“We are confident that these molecules originate from the subsurface ocean of Enceladus, enhancing its habitability potential,” lead author Nozair Khawaja of the Free University of Berlin said in an email.
Cassini, launched in 1997 as a joint mission of NASA, the European Space Agency (ESA), and the Italian Space Agency, ended its mission in 2017 with a controlled plunge into Saturn’s atmosphere. Researchers now advocate for new missions to probe Enceladus more directly.
“Having a variety of organic compounds on an extraterrestrial water world is simply phenomenal,” Klenner said.
ESA has begun early planning for a potential lander mission to Enceladus decades from now, while China has also proposed a landing. Meanwhile, NASA’s Europa Clipper is en route to Jupiter’s moon Europa, another prime target in the search for habitable environments, with arrival planned for 2030. ESA’s Juice mission is also headed to Jupiter to study Europa and other icy moons believed to conceal subsurface oceans.
“Underground oceans on moons are perhaps the best candidates for the emergence of extraterrestrial life in our solar system. This work only confirms the need for further studies,” said Nigel Mason, a physics professor at the University of Kent who was not involved in the research.
