NASA Discovers Essential Component for Life on Saturn’s Moon
The search for alien life has received a significant boost.
Scientists have discovered that phosphorus, a key building block of life, resides in the ocean beneath the icy surface of Saturn’s moon Enceladus.
The discovery was based on a review of data collected by NASA’s Cassini probe, and was published Wednesday in the prestigious journal Nature.
Cassini began exploring Saturn and its rings and moons in 2004 before burning up in the gas giant’s atmosphere when its mission ended in 2017.
“This is an amazing discovery for astrobiology,” said Christopher Glein of the Southwest Research Institute, one of the authors of the paper, adding: “We have found abundant phosphorus in whole-ice samples that spray from the subsurface ocean.”
Geysers at Enceladus’ south pole spew icy particles into space through fissures in the surface, feeding Saturn’s E ring—the faint ring outside the brighter main rings.
Scientists have previously found other minerals and organic compounds in ejected ice grains, but not phosphorus, which is an essential building block of DNA and RNA and is also found in the bones and teeth of humans, animals and even ocean plankton.
Simply put, life as we know it would not be possible without phosphorus.
While geochemical modeling had previously found that phosphorus was also likely to be present, and that prediction was published in an earlier paper, it’s one thing to predict something and another to confirm, Glein said.
“This is the first time this essential element has been found in an ocean outside of Earth,” added first author Frank Postberg, a planetary scientist at the Freie Universitat Berlin, in a NASA statement.
To make the new discovery, the authors combed through data collected by Cassin’s Cosmic Dust Analyzer and confirmed the findings by conducting laboratory experiments showing that Enceladus’ ocean contains phosphorus bound in various water-soluble forms.
Over the past 25 years, planetary scientists have discovered that worlds with oceans beneath a layer of ice are common in our solar system.
These include Jupiter’s moon Europa, Saturn’s largest moon Titan, but even the more distant body Pluto.
Although Earth-like planets with surface oceans must be located at a narrow distance from their host star to maintain the right temperature for life, the discovery of worlds with subsurface oceans increases the number of potentially habitable bodies that exist.
“With this discovery, Enceladus’ ocean is now known to meet what is generally considered the most stringent requirement for life,” Glein said.
“The next step is clear – we need to return to Enceladus to see if the habitable ocean is actually populated.”