A recent study conducted by New York University Abu Dhabi suggests that radiolysis, triggered by cosmic rays in galaxies, may serve as a potential energy source for microbial metabolism within the subsurface environments of rocky celestial bodies such as Mars, Europa, and Enceladus.
NASA’s Cassini spacecraft captured this stunning mosaic of Enceladus as it flew past this geologically active moon of Saturn on October 5, 2008. Image credit: NASA/JPL/Space Science Institute.
While ionized radiation is known for its detrimental effects on biological systems, such as causing damage to DNA and generating reactive oxygen species, it can also yield biologically beneficial outcomes.
Though direct exposure to high radiation levels can be harmful to biological activity, ionizing radiation can create numerous biologically useful products.
One such process involves the generation of valuable biological products through charged particle-induced radiolysis.
“We investigated the consequences of cosmic rays striking surfaces containing water or ice,” noted Dr. Dimitra Atli, PhD, from New York University Abu Dhabi, alongside colleagues from Washington University, the University of Tennessee, Rice University, and Santander University.
“The impact of these rays breaks down water molecules and releases tiny particles known as electrons.”
“Certain bacteria on Earth are capable of utilizing these electrons for energy, akin to how plants harness sunlight.”
“This phenomenon, known as radiolysis, allows for life to persist in dark, cold environments devoid of sunlight.”
This newly reorganized color view presents a massive surface of Europa. The image scale is 1.6 km per pixel, with the northern part of Europa on the right. Image credit: NASA/JPL-Caltech/Seti Institute.
Researchers utilized computer simulations to assess the energy output of this process on the icy moons of Mars, Jupiter, and Saturn.
These icy moons are believed to harbor liquid water beneath their thick ice crusts.
Findings indicate that Enceladus is the most promising candidate for supporting life in this manner, followed closely by Mars and Europa.
“This discovery reshapes our understanding of potential habitats for life,” Dr. Atri commented.
“Rather than confining our search to warm, sunlit planets, we can now consider cold, dark regions where water lies beneath the surface and is subjected to cosmic rays.”
“Life might exist in many more locations than previously thought.”
This image captured by Mars Express’s high-resolution stereo camera reveals an overview of Mars, with patches of yellow, orange, blue, and green on a muted gray background, depicting various surface compositions. Image credits: ESA/DLR/FU BERLIN/G. MICHAEL/CC BY-SA 3.0 IGO.
In their research, the authors introduce a new concept termed the Radiolysis Habit Zone.
Unlike the traditional “Goldilocks zone”—the region around a star where planets can sustain liquid water—this new zone emphasizes the potential for subsurface water that can be energized by cosmic radiation.
Given that cosmic rays are ubiquitous throughout the universe, this suggests that numerous additional locations may harbor life.
“These findings offer fresh directions for future space exploration,” remarked Reservers.
“Scientists can target the underground environments of these icy moons and Mars instead of solely searching for life on their surfaces.
“This study paves the way for thrilling new avenues in life exploration across the cosmos, implying that even the coldest and darkest regions may have conditions suitable for life.”
The study will be published in International Journal of Astrobiology.
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Dimitra Atri et al. 2025. Estimating the potential of ionizing radiation-induced radiolysis for microbial metabolism in Earth’s planets and moons with tenuous atmospheres. International Journal of Astrobiology 24:E9; doi:10.1017/s1473550425100025
Source: www.sci.news
