The Mars 2020 Candidate Landing Sites: A Magnetic Field Perspective

Abstract

We present an analysis of the remaining three candidate landing sites for Mars 2020, Columbia Hills (CH), Northeast Syrtis (NES) and Jezero (JE) from the perspective of understanding Mars' crustal magnetic field. We identify how the different sites can address each of six community‐defined paleomagnetic science objectives for Mars return samples. These objectives include understanding the early dynamo field and its variability, identification of magnetic minerals that carry magnetization in the samples, and characterization of any thermal and chemical alteration of samples. Satellite data have provided global and regional constraints on crustal magnetization, indicating strong magnetizations at CH and weak to no magnetization at JE and NES. However, the primary paleomagnetic interest—understanding the early dynamo—requires ground truth from a landing site at which pre‐Noachian and Early Noachian deposits are accessible. This requirement is most likely met by the site NES, which contains meggabreccia deposits, and it is therefore the highest priority landing site for magnetic field investigations. Importantly, a sample return mission has never been done, and so any of the three landing sites will provide critical, new data that will contribute to understanding the history of Mars' magnetic field and crustal mineralogy and, in turn, yield constraints on the planet's evolution.

Paleointensity and Rock Magnetism of Martian Nakhlite Meteorite Miller Range 03346: Evidence for Intense Small‐Scale Crustal Magnetization on Mars

“…Kereszturi and Chatzitheodoridis (2016) used crater diameters between 3 and 100 km and proposed a large region in the Amazonian lava plains containing 53 craters (Figure 6 a,b). Crustal magnetic field models from MGS (e.g., Cain et al, 2003;Langlais et al, 2004;Lillis, Frey, Manga, Mitchell, et al, 2008;Morschhauser et al, 2014) and MAVEN (Langlais et al, 2019;Mittelholz et al, 2018) data can be continued downward to the surface to compare with our paleomagnetic data. However, the effective spatial resolution of surface magnetic sources is approximated by the orbital altitude, which is ∼135 km for models including MAVEN data (Johnson et al, 2019;Langlais et al, 2019).…”

How to Live on Mars With a Proper Circadian Clock?

“…Mars has a crustal magnetic field magnetized by an ancient global dynamo field ∼4 Ga ago; however, it does not have a global dipole magnetic field like Earth. The dipole core field at the surface is weaker than the present core field at the surface of the Earth (Mittelholz et al, 2018;Stevenson, 2001). These differences in the Mars magnetic field will exert influences on the circadian rhythms of Earth emigrants.…”

Ground-Penetrating Radar Modeling Across the Jezero Crater Floor

“…It is therefore possible that magnetic properties could be noticeable for radar sounding on Mars. Regionally around the Mars 2020 landing site, specifically, the mapped crustal magnetization is weak [22], though it does not preclude substantial magnetic mineralogy in a demagnetized crust or localized magnetization that is undetectable at orbital altitudes. Spaceborne radars have been sounding the Martian crust's upper hundreds to thousands of meters [23,24], operating at lower frequencies and larger spatial scales compared to RIMFAX.…”