Polarized Cosmic Rays and Astrobiology
Updated: Apr 29, 2022
Muons have interesting properties that could have played a role in the emergence of life.
Muons are unstable particles with half-lives of a few microseconds. They are created by a decay involving the weak force, and they are spin-polarized on average. As we discussed last year, in ApJL 895 L11, this continuous spin-polarized cosmic radiation might explain the emergence of the particular handedness in biological molecules. We don’t know yet how the effect is exactly translated in terms of influence on biological evolution. We hope to be able to perform experiments in the future.
For our model to work, muons needs to be the dominant component of secondary cosmic rays. Cosmic rays provide a free available source of muons everywhere but the dominance of the muon component arises at different depths depending on the environment.
In a recent paper, we calculate spin polarized radiation doses at different prime target for the search of life in our solar system: Mars, Titan, Enceladus, Venus. Interestingly, Earth is the only body in the solar system where muons dominate the cosmic radiation at ground level.