NASA just made another historic finding of ocean worlds. The space agency announced that there is a subsurface energy source underneath Saturn's moon Enceladus. This could also mean that the moon has the right chemistry for alien life.

The finding gives hopefuls a new venue to focus the search for alien life. Aside from Saturn's moon Titan, Enceladus may also host thriving bacterial life in its oceans.

The finding is part of NASA's exploration of "ocean worlds" within the Solar System published in the journal Science. Data from Cassini and the Hubble Space Telescope were used for the study. Based on the paper by NASA, life forms can feed on the chemical energy from Saturn's moon Enceladus. In addition, scientists also found erupting plumes from Jupiter's moon Europa.

"This is the closest we've come, so far, to identifying a place with some of the ingredients needed for a habitable environment," Thomas Zurbuchen, associate administrator for NASA's Science Mission Directorate at its headquarters in Washington, said in a press release. "These results demonstrate the interconnected nature of NASA's science missions that are getting us closer to answering whether we are indeed alone or not."

The study also says that the hydrogen gas from Enceladus could provide an energy source. The hydrothermal activity originates from the seafloor of the moon. Microbes, if there's any, can survive given an ample amount of hydrogen from the subsurface energy source in Enceladus. Combining hydrogen and carbon dioxide is called "methanogenesis" that produce methane products. This process can also be observed on Earth.

What's surprising is that Saturn's moon Enceladus, which is farther away from the Sun than Earth, has all three primary ingredients for life -- liquid water, energy source and the correct chemicals such as hydrogen, oxygen, and sulfur. The finding greatly supports the habitability of the small, icy moon.

Although the oceans or liquid water of Enceladus is covered with solid ice layers, the hot water vents on its seabed provide subsurface energy that potentially provides molecules that can serve as a food supply for alien life forms.

NASA believes that drilling into Enceladus to collect samples half way across the Solar System would be difficult. Nevertheless, they are interested in collecting samples from the plumes that erupt from the surface of Saturn's moon Enceladus to further understand its chemistry.