THE POSSIBILITIES. “There is a possibility of life on icy objects in the interplanetary medium such as comets, and other bodies in the interstellar environment. This energy source could support life locked inside icy objects and facilitate efficient transportation conforming to the panspermia hypothesis. Because rogue or independent planets also receive a steady flux of this radiation, there is a possibility of a thriving subsurface ecosystem on such planets. Ground-based laboratory tests are suggested that can be conducted to validate the hypotheses presented here.”
https://royalsocietypublishing.org/doi/10.1098/rsif.2016.0459