Cosmic Rays May Sustain Life in Total Darkness, New Study Finds

Is it possible to live where there is no sunlight? A new study by an international research team led by Dimitra Atri from the Center for Space Science in Abu Dhabi offers a surprising answer: yes — if cosmic rays are nearby.

Energy from Below

The scientists modeled how high-energy particles, penetrating through ice and rock, trigger a process known as radiolysis — the breaking apart of water molecules and the release of electrons. This mechanism can supply energy to microorganisms even in complete absence of sunlight.

Planets and Moons in Focus

Using GEANT4 simulations, the researchers found:

• On Enceladus, a moon of Saturn, energy equivalent to 10 million ATP molecules per gram of ice per second can be generated at a depth of two meters.
• Mars, with its thin atmosphere, allows cosmic rays to reach its surface more easily.
• Europa, Jupiter’s moon with a thick ice shell, also appears to be a strong candidate.

A New Understanding of Habitable Zones

The team introduced the concept of a “radiolytic habitable zone.” Previously, the idea of habitability was limited to the so-called “Goldilocks zone” — the region around a star where liquid water can exist on a planet's surface. Now, the depth to which cosmic rays can penetrate becomes a key factor.

Earth-Based Evidence

Similar life forms already exist on Earth:

• The bacterium Desulforudis audaxviator lives 2.7 kilometers underground in a South African mine, relying solely on radiation for energy.
• Microorganisms near the Juan de Fuca Ridge survive by utilizing hydrogen produced in underwater rock formations.

Cosmic Missions to Test the Theory

Several upcoming missions aim to test this hypothesis:

• The Rosalind Franklin rover (ESA, 2028) will drill two meters into the Martian surface.
• NASA’s Europa Clipper will study the ice crust of Europa.
• The Enceladus Orbilander mission will collect samples from cryovolcanic plumes.

Broader Implications

If this hypothesis is confirmed, humanity will need to drastically expand its search for life — far beyond the familiar concept of “habitable zones” — and look in places we never imagined.