The study proposes a new definition: the "radiolitic habitable zone" - in contrast to the classic "habitable zone" (the region around a star that allows liquid water to exist on the surface), the radiolitic habitable zone focuses on places where there is water below the surface that can absorb energy from cosmic radiation.
A new study by researchers at New York University Abu Dhabi suggests that cosmic rays – high-energy particles coming from space – could generate enough energy to sustain life beneath the surface of planets and moons in the solar system.
The findings suggest that in certain subsurface regions, cosmic radiation may allow microbial life to exist, challenging the traditional assumption that life can only exist in areas heated by sunlight or geothermal activity. The study, published in the journalInternational Journal of Astrobiology , led by Professor Dimitra Attri, principal investigator at the Space Exploration Laboratory of the Center for Astrophysics and Space Sciences at NYUAD. “Life may survive in places we have never imagined,” said Professor Attri.
How cosmic rays can fuel life
The researchers studied how cosmic rays react when they come into contact with underground water or ice. When the energetic particles hit water molecules, they break them apart, releasing electrons. Certain types of bacteria on Earth are able to use those free electrons as a source of energy—similar to how plants use sunlight. This process, called radiolysis, could provide the energy needed to sustain life even in cold, dark environments where sunlight doesn’t penetrate.
To test the hypothesis, the team used computer models to estimate the energetic potential of radiolysis on Mars and the icy moons of Jupiter and Saturn. These celestial bodies are thought to contain liquid water beneath their icy surfaces. According to the simulations, Saturn's moon Enceladus has the highest potential for supporting life through this mechanism, followed by Mars, and finally Jupiter's moon Europa.
"This discovery changes the way we think about places where life might exist," Atari added. "Instead of just looking for warm planets with sunlight, we can now also consider cold, dark places, as long as they have underground water and exposure to cosmic rays. Life could exist in many more places than we thought."
Defining a new life zone: the radiolytic life zone
The study proposes a new definition: the “radiolitic habitable zone” – In contrast to the classic “habitable zone” (the region around a star that allows liquid water to exist on the surface), the radiolitic habitable zone focuses on places where there is subsurface water that can absorb energy from cosmic rays. Since cosmic rays are widespread throughout space, there may be many more places in the universe where life could exist.
The findings suggest new directions for planning future space missions. Instead of looking for signs of life only on the surface, scientists might also focus on subsurface environments on Mars and its icy moons—using tools that can detect chemical energy generated by cosmic rays.
The research opens up exciting new possibilities in the search for life beyond Earth, suggesting that even the darkest and coldest places in the solar system may contain the conditions necessary for life to exist.
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One response
If we find an alien civilization – I'm interested in knowing what way they found to live in peace and harmony all together ("utopia"). After all – if we discover them at the level of civilization – there is a very small chance that we will find them less developed than us.