A place that should, in principle, be able to sustain life
An enormous hidden ocean lies trapped in fractured rock deep beneath Mars, containing sufficient water to cover the entire planet with a mile-deep layer. The water likely seeped underground billions of years ago when Mars lost its surface water, making it inaccessible with current Earth drilling technology.
- Underground reservoir lies 7-13 miles beneath Mars' surface
- Contains enough water to cover the entire planet with a mile-deep layer
- Discovered using seismic data from NASA's InSight Lander (2018-2022)
- Deepest hole ever drilled on Earth reaches only 7.6 miles
Scientists using NASA's InSight Lander seismic data discovered a vast underground water reservoir 7-13 miles beneath Mars' surface containing enough liquid to cover the planet with a mile of water, potentially harboring microbial life.
Beneath the rust-colored surface of Mars, trapped in fractured rock between seven and thirteen miles down, lies an ocean. Not a small one. Scientists analyzing seismic data from NASA's InSight Lander have concluded that this hidden reservoir contains enough water to blanket the entire planet in a mile-deep layer. The discovery, published in August in the Proceedings of the National Academy of Sciences, suggests that when Mars lost its surface water roughly 3.5 billion years ago, much of it didn't vanish into space. Instead, it seeped downward, pooling in the fractured crust where it remains today, locked away and inaccessible.
The InSight Lander, which operated as a robotic seismology station from 2018 to 2022, recorded Martian earthquakes and tremors caused by meteor impacts and volcanic activity. These vibrations traveled through the planet's interior, and researchers fed the resulting data into mathematical models similar to those used on Earth to locate aquifers and oil deposits. What emerged from this analysis was a map of Mars' deep structure—its crustal thickness, core depth, core composition, and mantle temperature. Most significantly, it revealed that the lower crust likely consists of a mosaic of broken igneous rock saturated with liquid water.
What makes this discovery tantalizing is not just the water itself, but what it might contain. Michael Manga, a geophysicist at UC Berkeley and co-author of the study, noted that water is fundamental to life as we understand it. He pointed out that on Earth, life thrives in the deepest mines and at the ocean floor, in conditions of extreme pressure and darkness. There is no obvious reason why a subsurface Martian ocean would be fundamentally different. "We haven't found any evidence for life on Mars," Manga said, "but at least we have identified a place that should, in principle, be able to sustain life."
The question of where Mars' water went has haunted planetary scientists for decades. The planet's surface bears unmistakable scars of its wetter past—dried riverbeds, ancient deltas, and lake basins crisscross the landscape. Yet something catastrophic happened roughly 3.5 billion years ago. Mars' climate shifted abruptly, and its surface water vanished. Scientists have proposed various culprits: a sudden loss of the planet's protective magnetic field, a massive asteroid impact, or even ancient microbial life that somehow triggered runaway climate change. The new findings suggest at least part of the answer: the water didn't disappear. It went down.
There is, however, a significant catch. Accessing this subsurface ocean would require drilling technology that does not yet exist. The deepest hole ever dug on Earth, the Kola Superdeep Borehole in Russia, reaches only 7.6 miles into our planet's crust—barely past the upper boundary of where Martian water is thought to reside. A mission to drill into Mars and sample this hidden ocean remains firmly in the realm of future possibility, not present capability.
Yet the search for life on Mars is not waiting for such a breakthrough. NASA's Perseverance rover has been collecting geological samples from Jezero Crater since 2021, gathering dust and rock that may already contain evidence of ancient microbial life. Those samples, along with continued surface exploration, represent the near-term frontier of the hunt. But the discovery of this vast underground reservoir has shifted the conversation. It has identified not just a place where life might have existed in Mars' distant past, but a place where it might exist right now, in the cold darkness, waiting to be found.
Citas Notables
Water is necessary for life as we know it. Deep mines host life, the bottom of the ocean hosts life. We haven't found evidence for life on Mars, but we have identified a place that should be able to sustain life.— Michael Manga, UC Berkeley geophysicist and study co-author
La Conversación del Hearth Otra perspectiva de la historia
How did scientists figure out there was an ocean down there if they can't see it?
They used earthquakes. The InSight Lander recorded Martian quakes for four years, and the seismic waves that rippled through the planet told them about the rock layers below—their thickness, density, composition. It's the same technique geologists use to find oil and water on Earth.
So they're certain the water is there?
As certain as you can be without drilling down and touching it. The data strongly points to a fractured rock layer saturated with liquid. But yes, there's always uncertainty in these models.
Why would life survive down there? It's freezing, it's dark, there's no sunlight.
Life on Earth does exactly that. In deep mines, in the ocean trenches, in aquifers miles underground—organisms thrive without sunlight. They use chemical energy instead. Mars' subsurface could work the same way.
Could we actually drill down there someday?
Theoretically, yes. But we've never drilled more than 7.6 miles into Earth. Mars is harder to work on, the drilling would be more complex, and the cost would be enormous. It's not happening anytime soon.
So what's the point of finding it if we can't reach it?
It changes how we think about Mars. It tells us the planet isn't dead—it has liquid water, it has energy, it has the basic ingredients for life. And it gives us a reason to keep looking, to keep asking questions about what's really down there.