Surviving on Saturn moon
Study finds a life form on Earth that may do fine on icy Enceladus.
With its subsurface ocean and geysers spewing water and complex organic molecules, Saturn’s moon Enceladus is one of the most promising places to look for extraterrestrial life in the solar system, scientists say.
But what exactly would life on Enceladus look like, and how would it function?
After all, the theoretical organisms growing and multiplying deep below the ice moon’s surface would have no access to the sunlight that fuels the vast majority of life on Earth.
There is no available oxygen to work with, and a tremendous amount of pressure to contend with if an organism hopes to derive energy from the chemical reaction between Enceladus’ subsurface ocean and its rocky core.
Despite these hurdles, a team of researchers found that there is at least one life form on Earth that probably would do just fine living under the presumed conditions on Enceladus. It’s a single-celled organism known as
In a paper published Tuesday in Nature Communication, researchers show that
No spacecraft has penetrated Enceladus’ frozen crust, but NASA’s Cassini spacecraft did fly through great plumes of material that were spewing from the moon’s south pole.
These passes revealed that Enceladus’ internal ocean is made primarily of water, but the spacecraft’s instruments also detected methane, carbon dioxide, ammonia, molecular nitrogen and molecular hydrogen, among other compounds.
To see if any life forms on Earth could survive on Enceladus, the authors turned to three types of microbes known as methanogenic archaea. These are single-celled organisms that grow in the absence of both sunlight and oxygen, and produce methane as a metabolic product.
Here on Earth you can find methanogenic archaea in marine sediments, salt marshes and in the human gut, where they are partly responsible for flatulence and belching.
After attempting to grow archaea in a variety of conditions, the authors decided to work exclusively with
Over the next series of experiments, they found that
The new study shows how life as we know it
“Our study is a physiological, microbiological, geological study, and the results from lab experiments must be very carefully interpreted,” he said.