New Books Network James Welsh et al., "Weathering Space" (American Scientist 114:1 2026)
Dec 31, 2025
James Welsh, a radiation oncologist and researcher, delves into the radiation hazards of deep-space missions. He highlights how past missions benefited from Earth's magnetic shielding but warns that future explorations, especially to Mars, face significant risks. Topics include the intricacies of ionizing radiation and its biological effects, the limitations of conventional shielding, potential strategies like layered materials, and even intriguing ideas like using fungi for protection. Welsh paints a vivid picture of the challenges that await astronauts beyond our planet.
AI Snips
Chapters
Transcript
Episode notes
Magnetosphere Is A Life-Saving Cocoon
- Early missions stayed within Earth's magnetosphere so astronauts avoided the worst charged-particle radiation.
- Once you leave the magnetosphere, unmitigated space radiation becomes a major, invisible hazard.
LET, Not Energy, Predicts Biological Damage
- Linear energy transfer (LET) measures ionizations per distance and predicts biological harm better than particle energy.
- High-LET radiation causes more damage per unit length than low-LET radiation even if its total energy is lower.
Primary Rays Spawn Secondary Radiation
- Primary cosmic rays originate above the atmosphere and create secondary particles when they strike atmospheric nuclei.
- Secondary cosmic rays (electrons, neutrons, muons) can multiply radiation exposure at Earth's surface.