This plume is correlated with a thermal spot of interest, and if the two are connected, says NASA, it could help shed light on the nature of the moon's activities.
Ice plumes shooting into space from the ocean-bearing moon contain hydrogen from hydrothermal vents, an environment that some scientists believe led to the rise of life on Earth.
"The discovery of native molecular hydrogen [H2] completes the set of what I would call the "basic" requirements for life as we know it: liquid water, organic molecules, minerals, and an accessible source of "free" energy", Lunine explained to Gizmodo.
The paper by researchers with the Cassini mission, published Thursday in Science magazine, says that the hydrogen gas - which could potentially provide a source of chemical energy for the existence of life - is found in Enceladus' frozen ocean.
The Cassini mission's deepest dive into the plume took place on October 28, 2015 - and found its composition to be 98 percent water, one percent hydrogen, and a mixture of other molecules including carbon dioxide, methane, and ammonia.
"Now, Enceladus is high on the list in the solar system for showing habitable conditions", said Hunter Waite, one of the study s leading researchers.More news: Thermonuclear war may break out anytime: North Korea's United Nations deputy representative
"Confirmation that the chemical energy for life exists within the ocean of a small moon of Saturn is an important milestone in our search for habitable worlds beyond Earth", Spilker said in a statement.
Results from the agency's Cassini spacecraft and the Hubble Space Telescope indicate hydrogen exists in the form of hydrogen plumes on Europa - one of the moons of Jupiter and Enceladas, one of the moons associated with Saturn.
Image: Is this the only place beyond Earth with the conditions for life? The team suggests that this phenomenon is a chemical effect of interactions between the rocky core and warm water from the underground ocean of the moon.
"In 2005, Cassini, orbiting around Saturn, flying by the moons of Saturn with close flybys of Insolitus, it observed huge plumes of water emanating from cracks".
Meanwhile, Cassini's longstanding mission is soon coming to an end. If that is the case, then it is also reasonable to think that microbe life - if it exists - could be flourishing due to a process known as "methanogenesis".
As for what's next, NASA will launch a Europa Clipper mission in the 2020s based off of the Hubble's monitoring of Europa, and Cassini's look into Enceladus' plume.