Space radiation, especially when long-term missions to Mars are undertaken, poses a significant threat to astronauts’ health. Unlike Earth, Mars doesn’t have an intrinsic global magnetic field. Additionally, Mars’ atmosphere is too thin and weak to effectively shield against radiation.
Understanding the radiation environment on Mars is crucial for future human settlements. Mars doesn’t have an intrinsic magnetic field. Galactic cosmic radiation (GCR), particles could interact directly with Mars’ atmosphere and propagate through it before reaching the surface.
In a new study, scientists modeled the Martian radiation environment induced by omnipresent cosmic rays in Mars’s atmosphere and terrain. They used the state-of-the-art modeling toolthe Atmospheric Radiation Interaction Simulator (AtRIS), and radiation data collected by NASA’s Curiosity rover.
They simulated GCR exposure on the planet’s surface and measured how deeply it penetrates the surface dirt and rock. They found that radiation produced by heavy-ion ions can be reduced by using higher surface pressures. The maximum radiation dose was approximately 12 inches (30 cm) deep in the regolith.
Scientists calculated the effective dose under different surface pressures and heliospheric modulation conditions to determine the optimal shielding depths.
The study authors pointed out that “For a given threshold of the annual biologically weighted radiation effective dose, for example, 100 mSv, the required regolith depth ranges between 1 and 1.6 m. At a deep crater where the surface pressure is higher, the needed extra regolith shielding is slightly smaller.”
Understanding how Martian material is affected by GCRs and the role Mars’ atmosphere plays in altering radiation exposure is a step forward in developing a potential base on Mars. This study will aid in reducing radiation hazards by creating future Martian dwellings that use natural surface material for shielding protection.
Journal Reference:
- Jian Zhang et al. From the Top of Martian Olympus down to Deep Craters or Beneath, Mars Radiation Environment at Different Atmospheric & Regolith Depths. DOI: 10.1029/2021JE007157
