In 2015, the Cassini spacecraft swooped through the vapor plumes emanating from the south pole of the icy moon, and NASA has finally announced what it found during this sniff test: Enceladus's underground ocean might possess conditions similar to those found in Earth's undersea, hydrothermal vents. From these observations scientists have determined that almost 98 percent of the gas in the plume is water, about 1 percent is hydrogen and the rest is a mixture of other molecules including carbon dioxide, methane and ammonia.
The energy can be obtained from the combination of hydrogen and carbon dioxide dissolved in water.
Zurbuchen added that the missions were getting humans closer to understanding whether they were "indeed alone or not".
Our solar system is home to a number of known or suspected ocean worlds (vaguely defined as a planet or moon with a substantial portion of its surface covered by water).
The findings were reported Thursday in the journal Science by a team from Southwest Research Institute in San Antonio.
Prof Hunter Waite, an investigator for Cassini's mass spectrometer, which detected the hydrogen, said: "The plume contains chemical signatures of water-rock interaction between the ocean and a rocky core". The only ingredients Cassini hasn't yet confirmed are present are phosphorus and sulfur in the moon's oceans, but that's still something researchers studying the planet expect to find, given the apparent geological makeup of Enceladus.
The space agency says Saturn's icy moon called Enceladus has nearly all the ingredients to support life.
The ingredients required for life are liquid water, energy sources and chemicals such as carbon, hydrogen, oxygen, nitrogen, sulfur and phosphorus.
Specifically, hydrogen gas is thought to be coming from sub-sea vents and into the oceans of Enceladus, where it would provide the energy required their to support life forms including microbes.
"We now know Enceladus has nearly all the ingredients that you need to support life as you know it on Earth", said Linda Spilker, a Cassini project scientist, during a briefing that announced the new findings.
As for Europa, an icy moon orbiting Jupiter similar in size to Earth's, NASA reports that its "plumes could be a real phenomenon" by popping up in the same region in 2016 as it did in 2014.
In a press release for the briefing, NASA noted that the new results will affect the space agency's multi-billion-dollar Europa Clipper mission.