'Lost City' Deep Under The Ocean Is Unlike Anything We've Ever Seen Before on Earth

Part of the Mid-Atlantic Ridge

Surely submariners have known about the feature for a long time . . .

from the article:
the Lost City Hydrothermal Field is the longest-lived venting environment known in the ocean. Nothing else like it has ever been found.

"This is an example of a type of ecosystem that could be active on Enceladus or Europa right this second," microbiologist William Brazelton told The Smithsonian in 2018, referring to the moons of Saturn and Jupiter.

"And maybe Mars in the past."