土卫二理论上可能存在外星生物

Saturn's icy moon Enceladus could theoretically be home to methane-producing alien life, NASA said Thursday.

美国宇航局周四表示，冰冷的土星卫星土卫二理论上可能存在释放甲烷的外星生物。

Researchers made the announcement based on data from 2015, when the spacecraft Cassini detected the presence of hydrogen during a flyby through a plume of gas and ice erupting from Enceladus' south pole. The hydrogen, which is escaping into space from a hydrothermal vent on the moon's seafloor, could be a sign of methanogenesis, a form of anaerobic respiration in which microbes produce methane.

"This is a very significant finding because the hydrogen could be a potential source of chemical energy for any microbes that might be in Enceladus' ocean," Linda Spilker, a scientist at NASA's Jet Propulsion Laboratory, said Thursday at a press conference.

"We now know that Enceladus has almost all of the ingredients you would need to support life as we know it on Earth," she said.

The findings were published Thursday in the journal Science.