JACKSONVILE, Fla. – The oceans are a good starting point to find life. Earth's first organisms evolved in our planets early seas. Now NASA scientists announced the discovery of oceans on the moons of Jupiter and Saturn which appear to have ingredients that can feed life.
Life requires three primary ingredients: liquid water; a source of energy for metabolism; and the right chemical ingredients, primarily carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur.
Enceladus, Saturn's small icy moon, has nearly all of these ingredients for habitability.
“This is the closest we've come, so far, to identifying a place with some of the ingredients needed for a habitable environment,” said Thomas Zurbuchen, associate administrator for NASA's Science Mission Directorate at Headquarters in Washington. ”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 paper from researchers with the Cassini mission, published in the journal Science, indicates hydrogen gas, which could potentially provide a chemical energy source for life, is pouring into the subsurface ocean of Enceladus from hydrothermal vents in the seafloor.
The presence of ample hydrogen in the moon's ocean means that microbes – if any exist there – could use it to obtain energy by combining the hydrogen with carbon dioxide dissolved in the water. This chemical reaction, known as "methanogenesis" because it produces methane as a byproduct, is at the root of the tree of life on Earth, and could even have been critical to the origin of life on our planet.
"Although we can't detect life, we've found that there's a food source there for it. It would be like a candy store for microbes," said Hunter Waite, lead author of the Cassini study.
There is also evidence water is spraying 62 miles above Jupiter's moon Europa. New images bolster evidence that the Europa plumes could be a real phenomenon, flaring up intermittently a region on the moon's surface that is unusually warm containing cracks in the moon’s icy crust. Researchers speculate that, like Enceladus, this could be evidence of water erupting from the moon’s interior.