The Cassini space probe may have found water on Saturn's Enceladus moon, NASA said on Thursday.
"NASA's Cassini spacecraft may have found evidence of liquid water reservoirs that erupt" like geysers in the United States' Yellowstone park, the US space agency said in a statement.
"The rare occurrence of liquid water so near the surface raises many new questions about the mysterious moon," NASA said.
"We realize that this is a radical conclusion -- that we may have evidence for liquid water within a body so small and so cold," said Carolyn Porco, Cassini imaging team leader at the Space Science Institute in Boulder, Colorado.
"However, if we are right, we have significantly broadened the diversity of solar system environments where we might possibly have conditions suitable for living organisms," Porco said.