For its penultimate visit to the Saturnian moon Enceladus, the Cassini spacecraft will get hosed down by an alien ocean. On October 28, the probe will fly about 48 kilometers over the moon’s south pole and sample subsurface seawater that blasts through cracks in the ice. The measurements will help researchers figure out how suitable the seas of Enceladus are for extraterrestrial life.
Any hydrogen molecules detected within the fountains could confirm the presence of hydrothermal vents at the bottom of the ocean reported earlier this year. The spacecraft will also look for complex organic molecules carried aloft by the erupting water, though its instruments won’t be able to tell if the molecules come from aquatic aliens or not.
This is not Cassini’s first geyser dive, but it will be its last — and its deepest. The probe’s final visit to Enceladus will be on December 19, during which it will measure heat emanating from the ice cracks that etch across the moon’s south pole.