New research shows cosmic rays may help microscopic life survive underground on Mars and icy moons by creating energy through radiolysis. This challenges the idea that life needs sunlight, opening new paths in the search for extraterrestrial life.
Life Without Sunlight
Some microbes may survive without sunlight by using energy from cosmic rays interacting with underground water a process called radiolysis.
New research is changing the way scientists think about where life might exist in our solar system. A study from New York University Abu Dhabi suggests that cosmic rays—high-energy particles from space—could provide the energy needed for microscopic life to survive underground on planets like Mars and icy moons such as Enceladus and Europa.
The study, published in the International Journal of Astrobiology, questions the long-standing belief that life requires sunlight or geothermal heat to survive. It was conducted by Dimitra Atri, the lead researcher at the Space Exploration Laboratory within NYU Abu Dhabi’s Center for Astrophysics and Space Science (CASS).
Until now, scientists believed that life needed sunlight or heat from volcanic activity to exist. But this new study shows that life could survive in cold, dark environments—far from the warmth of a star—if there’s water or ice underground.
Here’s how it works: When cosmic rays hit underground ice or water, they cause a reaction called radiolysis. This process breaks water molecules apart and releases electrons—tiny particles that certain bacteria on Earth can use as energy. These bacteria don’t rely on sunlight; instead, they get their energy from chemical reactions. That means similar life forms could possibly live on Mars or the frozen moons of Jupiter and Saturn.
The research team ran computer simulations to see how much energy this process could generate. Among all the places studied, Saturn’s moon Enceladus showed the most promise. Mars came next, followed by Jupiter’s moon Europa.
“This discovery changes the way we think about where life might exist,” said lead researcher Dimitra Atri, who heads the Space Exploration Laboratory at NYUAD’s Center for Astrophysics and Space Science. “We now know that sunlight isn’t always necessary—cosmic radiation and buried water might be enough.”
The study introduces the idea of a “Radiolytic Habitable Zone.” Unlike the traditional “Goldilocks Zone,” which focuses on finding planets that are not too hot or too cold for liquid water on the surface, this new zone looks for places with underground water that can be energized by cosmic rays.
This finding is important because it offers new guidance for future space missions. Instead of just searching the surface of planets and moons for signs of life, scientists might now look below the surface—where cosmic rays may have created energy that helped life survive.
In short, the universe might be more life-friendly than we thought—even in places that seem cold, dark, and lifeless.
Source: New York University
New York University Abu Dhabi, published in the International Journal of Astrobiology (August 3, 2025)
Research by: Dr. Dimitra Atri, Space Exploration Laboratory, NYUAD Center for Astrophysics and Space Science (CASS)