The findings were presented in papers published by researchers with NASA's Cassini mission to Saturn and work on the Hubble Space Telescope. The microbes could combine the carbon dioxide in water and hydrogen to gain energy. The gas could be a chemical energy source of life, scientists involved with the mission said.
The chemical ingredients of life include carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur.
Cassini project scientist Linda Spilker added that the confirmation - that the chemical energy for life exists within Enceladus' ocean - is an important milestone in mankind's search for habitable worlds beyond Earth.
On Earth, such hydrothermal vents support thriving communities of life in complete isolation from sunlight.
One of the Saturnian moon's most visible features is its ice plumes - enormous geysers that release water vapor into space.
Cassini has found that nearly all of these ingredients are there on Enceladus, a tiny icy moon at a distance of a billion miles away from Saturn. A plume of water had already been observed in the same spot, which is how scientists knew to be watching for it.
NASA announced on Thursday that its Cassini spacecraft mission to Saturn has gathered new evidence that there's a chemical reaction taking place under the moon's icy surface that could provide conditions for life.
The probe found the hydrogen when it made its last and closest pass through plumes at Enceladus' south pole on October 28, 2015.
This new finding is therefore an independent line of evidence supporting the theory of hydrothermal activity taking place in the ocean of Enceladus.
Cassini, NASA said, was never created to detect signs of life, but rather to simply record data of Saturn. The original plume was estimated to be about 30 miles (50 km) high, while the newly imaged jet extended about 62 miles (100 km) above the moon's surface. But our planet's mostly liquid surface appears to be an outlier among our system's oceans-most large reservoirs of water exist on planets and moons far from the sun's heat and therefore can exist only beneath a frozen solid crust.
That is a tough question to answer, according to Mary Voytek, an astrobiology senior scientist at NASA Headquarters. New observations from NASA's Galileo spacecraft suggests Europa's plume, like the plumes on Enceladus, is associated with warmer temperature readings.
The Europa Clipper is set to launch in the 2020s and will make close flybys to Europa to study the oceans there to determine whether or not the same thing is happening there as on Enceladus, and importantly whether or not the moon could possibly support life.