Scientists believe Jupiter’s moon Europa could be the best bet for finding extraterrestrial life within the solar system, and a recent study brings us one step closer to finding out for sure. According to a report from Discovery News, researchers from NASA have discovered enough oxygen and nutrients in the moon’s water to theoretically support multi-cellular life.

The study, published in the journal Geophysical Research Letters, reveals that the chemical composition of the subsurface ocean on Europa may be suitable to more complex forms of life than scientists initially imagined. The research reveals how the makeup of the subsurface sea has evolved over time, generating key components necessary for the development of life.

According to planetary scientists Steve Vance of NASA’s Jet Propulsion Lab in Pasadena, CA, “We’re studying an alien ocean using methods developed to understand the movement of energy and nutrients in Earth’s own systems. The cycling of oxygen and hydrogen in Europa’s ocean will be a major driver for Europa’s ocean chemistry and any life there, just as it is on Earth.”

Europa’s subsurface ocean is protected by a massive layer of ice, so collecting samples is particularly challenging. Scientists believe that the moon has a rocky core with deep cracks that have filled up with liquid water over time. Furthermore, the moon is thought lack volcanic activity, leading scientists to believe that cracks continue to develop, allowing more opportunities for water to drive geophysical processes that generate ingredients necessary for life.

For life to exist on Europa, there would need to be an oxidizing agent to react with the hydrogen produced by the water’s contact with the moon’s subsurface rocks. The study hypothesizes that as radiation from the sun breaks down the icy shield above the subsurface sea, oxidants are released into the water below.

“The oxidants from the ice are like the positive terminal of a battery, and the chemicals from the seafloor, called reductants, are like the negative terminal,” said Kevin Hand, a JPL researcher. “Whether or not life and biological processes complete the circuit is part of what motivates our exploration of Europa.”

A press release from NASA describing the details of the study can be found here.