Radiation Environment and Doses on Mars at Oxia Planum and Mawrth Vallis: Support for Exploration at Sites With High Biosignature Preservation Potential

Abstract

The first human missions on Mars will likely involve several astrobiology‐driven science operations, at sites with high biosignature preservation potential. Here, we present a study of the radiation environment induced by Galactic Cosmic Rays and Solar Energetic Particles at Oxia Planum, landing site of the European Space Agency ExoMars 2022 mission, and at two different locations in Mawrth Vallis, using the Monte Carlo GEometry ANd Tracking 4‐based code dMEREM (detailed Martian Energetic Radiation Environment Model). The radiation environment for solar minimum in 2009 and a period close to solar maximum during the declining phase of solar cycle 23 appears similar at the different sites, with the deepest Mawrth Vallis location having a slightly enhanced γ‐ray contribution, due to a higher modulation of fast neutrons by the more water‐rich regolith. The comparison with the Dose Equivalent from an updated extrapolation of 7+ years data from the Radiation Assessment Detector (RAD) onboard the Curiosity rover highlights the importance of input modulation conditions, some drawbacks of the galactic cosmic ray model used here, and the need to include heavy ions, the three aspects affecting differently the estimations for solar maximum and minimum. The dependence of doses on surface pressure highlights a possible influence of the different dust loading at the different sites. Estimated exposure levels for a 1‐year stay and for a short stay in Arabia Terra, the latter including a October 28, 2003 event with a fluence an order of magnitude higher than the relevant September 2017 event detected by RAD, leave reasonable to large safety margins.

From the Top of Martian Olympus to Deep Craters and Beneath: Mars Radiation Environment Under Different Atmospheric and Regolith Depths

“…Recently, Da Pieve et al. (2021, Table 3) calculated the annual dose equivalents to be about 130 and 230 mSv for solar maximum and minimum conditions, respectively. Considering that they have ignored the contribution by GCR heavy ions ( Z > 2) and have used different particle transport models and Mars environment setups, our calculations are in acceptable agreement with theirs.…”

Insights into the Survival Capabilities of Cryomyces antarcticus Hydrated Colonies after Exposure to Fe Particle Radiation

“…The ongoing and future in situ life-detection missions on planetary bodies of our solar system (e.g., Mars) should drill the surface [ 47 , 48 ] in order to detect signs of past or present life. Assessing the biomarkers preservation under a highly radiative environment is of outmost importance to support these missions and to estimate the stability/degradation rates of biological molecules [ 49 ]. Besides, the investigation of the techniques could be used to evaluate the hypothetical biomolecules damages and is a test bed for the future Mars samples return (MSR) on Earth [ 50 ].…”

Validation of dMEREM, the Detailed Mars Energetic Radiation Environment Model, with RAD Data from the Surface of Mars

“…The Mars Energetic Radiation Environment Models, MEREM (Gonçalves et al, 2009), are ionising radiation environment characterization models for Mars, developed for the European Space Agency under the MarsREM project. The detailed Martian Energetic Radiation Environment Model (dMEREM) is a Geant4 based model that predicts the particle radiation environment on Mars atmosphere surface and on Phobos and Deimos (McKenna-Lawlor et al, 2012a), (McKenna-Lawlor et al, 2012b), (Da Pieve et al, 2021). eMEREM, the engineering Martian Energetic Radiation Environment Model uses a set of pre-computed response functions based on the FLUKA radiation transport code (Ferrari et al, 2005;Böhlen et al, 2014) to calculate the shielding effects of the atmosphere and surface for a range of mono-energetic proton and helium nuclei sources.…”