Beneath the crushing depths of the Atlantic Ocean, something extraordinary has been quietly thriving for over 120,000 years.
A jagged labyrinth of towering carbonate structures rises from the seafloor, ghostly blue in the dim light of exploration vehicles.
This isn’t a mythical lost city—it’s a real place, and it could hold the key to understanding the origins of life on Earth.
This is the Lost City Hydrothermal Field, a unique underwater ecosystem unlike anything else known to science.
More than 700 meters (2,300 feet) below the ocean’s surface, these spires and monoliths—some as tall as a 20-story building—stand as silent sentinels of Earth’s ancient past.
But this alien-like landscape isn’t just a geological wonder; it may also harbor profound implications for life beyond our planet.
A Fortress of Life in the Deep
Unlike the more famous hydrothermal vents known as black smokers, which rely on the intense heat of magma, the Lost City’s ecosystem is powered by a different kind of chemical reaction.
Here, the Earth’s mantle reacts with seawater, releasing a steady stream of hydrogen and methane—gases that provide sustenance for entire microbial communities, even in the absence of oxygen or sunlight.
Bacteria thrive in these cracks and crevices, forming the foundation of an ecosystem that includes snails, crustaceans, and even the occasional deep-sea eel.
These organisms survive in conditions that seem almost otherworldly, prompting researchers to wonder: Could similar environments exist elsewhere in our solar system?
A Potential Blueprint for Alien Life
The implications of the Lost City stretch far beyond Earth.
Unlike black smokers, which are relatively short-lived, the Lost City has been active for at least 120,000 years, possibly much longer.
The hydrocarbons produced here are not derived from sunlight or atmospheric carbon dioxide but are instead created through deep-sea chemical reactions.
This process mimics what scientists suspect could be happening on icy moons like Enceladus and Europa, where subsurface oceans interact with a rocky core, potentially generating the conditions needed for life.
“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.
“And maybe Mars in the past.”
A Different Kind of Hydrothermal Vent
For decades, scientists have looked to black smokers as potential sites for the origin of life.
These vents produce mineral-rich plumes heated by magma, supporting unique biological communities.
However, the Lost City operates on a different timescale and chemical process.
- Black smokers release iron- and sulfur-rich minerals, but the Lost City produces up to 100 times more hydrogen and methane.
- The tallest structure in the Lost City, Poseidon, rises over 60 meters (nearly 200 feet) high, dwarfing typical black smoker vents.
- The Lost City’s vents are much more alkaline, with temperatures around 40°C (104°F)—a stark contrast to the scalding 400°C (750°F) temperatures of black smokers.
These distinctions have led some scientists to speculate that the Lost City’s conditions are actually a better match for the origins of life on Earth than the high-energy environments of black smokers.
The Mantle Core Sample
In 2024, researchers achieved a groundbreaking milestone—extracting a 1,268-meter-long core sample from the Lost City’s mantle rock.
This record-breaking sample could provide crucial evidence about the conditions under which life first emerged on Earth.
“This core could help us understand the chemistry that existed on early Earth,” said one researcher involved in the project.
If similar processes were happening billions of years ago, it strengthens the argument that life could have originated in environments just like the Lost City.
Deep-Sea Mining
Despite its scientific importance, the Lost City is under imminent threat. In 2018, Poland won the rights to mine the deep sea surrounding this fragile ecosystem.
While no direct mining operations are currently planned for the hydrothermal field itself, disturbances to the surrounding seabed could have devastating consequences.
Mining activities could stir up plumes of sediment, releasing toxic metals and potentially altering the delicate chemical balance that sustains the Lost City’s microbial life.
Scientists fear that without proper protection, this invaluable site could be irreparably damaged before its secrets are fully understood.
“This is a place unlike any other on Earth,” one scientist warned. “We have barely begun to study it, and yet we’re already putting it at risk.”
A Call for Protection
Given the Lost City’s scientific and potential astrobiological significance, some researchers are urging UNESCO to designate it as a World Heritage Site.
Such a classification would help ensure its protection from deep-sea mining and other destructive human activities.
For now, the Lost City stands as an ancient, silent testament to Earth’s resilience and the unrelenting force of life. Whether we preserve it—or destroy it—remains to be seen.
