Caltech scientists find evidence of ancient ocean on Mars
Updated
Updated · Wodne Sprawy · May 2
Caltech scientists find evidence of ancient ocean on Mars
12 articles · Updated · Wodne Sprawy · May 2
The study says water may once have covered up to one-third of the planet, with a shelf-like ring identified in Mars's northern hemisphere at depths of 1,800 to 3,800 metres.
Researchers Abdallah Zaki and Michael Lamb compared Martian topography with computer simulations of Earth's drained oceans, arguing rounded shelves, river deltas, coastal deposits and water-altered minerals support the ocean hypothesis.
The findings could sharpen the search for past extraterrestrial life and help guide future Mars missions, though major barriers including radiation, thin atmosphere, cold and uncertain usable water still challenge human settlement.
Mars had oceans and organic molecules. What is the final hurdle to proving ancient life really existed there?
With private firms eyeing Martian resources, can outdated treaties prevent a 'wild west' land grab on the Red Planet?
Unveiling Oceanus Borealis: How Mars' 3-Billion-Year-Old Coastal Shelf Proves a Long-Lived Northern Ocean
Overview
In April 2026, researchers from Caltech and the University of Texas revealed strong evidence for a vast ancient ocean, Oceanus Borealis, that once covered Mars' northern lowlands. They discovered a consistent coastal shelf and aligned river deltas, indicating a stable shoreline shaped by long-lasting water. This ocean formed 4.1 to 3.8 billion years ago, supported by a dense CO2 atmosphere creating a greenhouse effect. However, Mars lost its magnetic field around 4.1 billion years ago, allowing solar wind to strip away the atmosphere and cause global cooling, which led to the ocean's disappearance. Much of Mars' water became trapped deep underground, forming a vast subsurface aquifer that may have supported microbial life and offers a future resource for exploration. These findings reshape our understanding of Mars' climate history and guide upcoming missions searching for signs of past life.