WHAT'S THE PROBLEM, REALLY?
According to a paper on "Orbital and Planetary Challenges for Human Mars Exploration", the orbit around the planet contains high doses of cosmic radiation.
The radiation levels on Mars are significantly higher than those in ISS orbit, which poses a serious risk to human health.
In fact, even just 3 years on Mars' surface builds a radiation dose that exceeds the NASA astronaut career limit.
AND WHY DOES IT MATTER?
There are many health risks associated with heavy and/or prolonged exposure to radiation, such as:
- Increased risk of cancer (radiation-induced DNA mutations)
- DNA strand and tissue damage
- Cataracts
- Immunological effects
- Damage to the central nervous system (CNS)
and so on.
AND WHY DOES IT MATTER?
I would especially like to highlight the last point about damage to CNS. A study published on nature.com found that even low doses of charged particles caused lower cognitive performance in rodents, with very little signs of recovery between 12 and 24 weeks post-exposure. This was attributed to reductions in "dendritic complexity, spine density and altered spine morphology", as well as "disrupted synaptic integrity and increased neuroinflammation".
"Radiation-induced impairments in spatial, episodic and recognition memory were temporally coincident with deficits in executive function and reduced rates of fear extinction and elevated anxiety."
