When NASA researchers first realized in 2005 that Saturn's moon Enceladus has liquid water under its surface, they were stunned.
"Tremendously exciting," Cassini project scientist Linda Spilker told Popular Mechanics. "I sort of call it jaw-dropping because we were so certain that Enceladus was too small to support activity like this. We expected it to be frozen solid."
Since then, the Cassini spacecraft orbiting Saturn has sent back amazing visuals and data about this small watery moon, now considered one of the best places to look for life beyond Earth.
And today, NASA made the next big announcement about this promising place: The Cassini team found evidence of hydrothermal vents on Enceladus's ocean floor, which they document in a new study in Science.
These hydrothermal vents are fissures in the rocky core of Enceladus. They release water that has been heated by geothermal activity, and the jets of hot water carry minerals and nutrients that could support life.
Some of those compounds were detected by the Cassini spacecraft when it flew through the water geysers that erupt from Enceladus's surface. Microbes, algae, tube worms, crabs, and even fish swim around hydrothermal vents in Earth's oceans. Maybe a similar alien ecosystem exists on the seafloor of Enceladus.
"We know from looking at the hydrothermal vents on the Earth—there's no sunlight there—and yet if you look near a hydrothermal vent that has the heat energy and the nutrients that you need in the liquid water, you find a very thriving community of life," says Spilker. "You find tiny crabs and tube worms and a very thriving community around these hydrothermal vents well away from sunlight. So we wonder, could life have begun in the same way in the Enceladus ocean as well?"
Could it just be?
