When were hydrothermal vents first discovered?

Hydrothermal vents were first discovered in 1977 during an expedition to the Galápagos Rift. Scientists found superheated, mineral-rich water escaping from the seafloor and supporting dense communities of unusual organisms. The discovery was groundbreaking because these ecosystems were powered by chemosynthesis rather than sunlight. Instead of using photosynthesis, microbes used chemicals such as hydrogen sulfide as an energy source. This finding changed ideas about where life can exist on Earth and possibly elsewhere in the solar system.