June 27 (UPI) -- Scientists have found evidence of complex organic molecules on Saturn's moon Enceladus. The chemical signals were identified among spectrometry data collected by NASA's Cassini spacecraft.
"We are, yet again, blown away by Enceladus," Christopher Glein, a space scientist at the Southwest Research Institute, said in a news release. "Previously we'd only identified the simplest organic molecules containing a few carbon atoms, but even that was very intriguing."
The new data revealed the presence of complex organic molecules with masses greater than 200 atomic mass units.
"That's over ten times heavier than methane," Glein said. "With complex organic molecules emanating from its liquid water ocean, this moon is the only body besides Earth known to simultaneously satisfy all of the basic requirements for life as we know it."
The molecules were collected and analyzed by Cassini's Cosmic Dust Analyzer and the SwRI-led Ion and Neutral Mass Spectrometer during the craft's last few orbits. Cassini ended its mission, descending into Saturn's atmosphere, in 2017.
During its final orbits, Cassini collected samples both form the icy plumes emanating from Enceladus' ocean, as well as Saturn's E-ring, which is formed by ice particles that escape the moon's gravity.
Scientists described their analysis of the Cassini data this week in the journal Nature.
"Even after its end, the Cassini spacecraft continues to teach us about the potential of Enceladus to advance the field of astrobiology in an ocean world," Glein said.
Early flybys revealed the presence of molecular hydrogen originating from the moon's subsurface ocean. Scientists continue to consider the Saturn moon a top target in the search for extraterrestrial life.
"A future spacecraft could fly through the plume of Enceladus, and analyze those complex organic molecules using a high-resolution mass spectrometer to help us determine how they were made," Gelin said. "We must be cautious, but it is exciting to ponder that this finding indicates that the biological synthesis of organic molecules on Enceladus is possible."