The Impact of Solar Energetic Particles at Mars’ radiation environment: A synergistic approach combining measurements and Modeling efforts

Radiation is one of the most important risks to deep space exploration programs such as manned missions to the Moon and Mars. In preparation for such programs, it requires a thorough understanding of interplanetary space weather conditions and a timely forecast of their potential effects as a baseline for the development of mitigation strategies. 

 

Radiation damage in space comes mainly from two sources, Galactic Cosmic Rays (GCRs) and Solar Energetic Particles (SEPs). In particular, intense SEP events could result in very high doses in a short time period that may exceed the threshold to induce deterministic radiation effects and to result in severe damages to humans and equipment leading to the failure of the entire mission. SEP events with radiation hazards, despite of being rather infrequent and sporadic, are however very difficult to forecast and remain as a major challenge for space weather studies in preparation for future deep space and Mars missions.

 

Specifically speaking, the SEP radiation reaching an astronaut on a Mars may be completely different from of that detected at (or predicted for) Earth’s vicinity, including the SEP onset time, spectra evolution, radiation intensity etc. This is due to (1) the different location of Mars and connectivity to the acceleration source which allow it to have difference access to the SEP population, and (2) the different planetary environment which modifies the energy and composition of the particles due to the interactions of primary particles with the atmosphere/regolith and the generation of secondaries. The synergistic analysis and modeling of these two processes are particularly important to understand and eventually forecast SEPs and their radiation effects on Mars in preparation for mitigating their potential hazardous effects.  We also emphasize the utmost importance of utilizing multi-spacecraft particle measurements at Mars and also other heliospheric locations to better understand such extreme events and their radiation effects for future deep space explorers.