Synthesis of Venera 13 Analog Basalt Samples for Oxidation and Degassing Experiments

Experimental studies on the redox behaviors of Venus surface materials are important for preparing instrumentation and landing gear for upcoming NASA Venus missions DAVINCI and VERITAS, and ESA’s EnVision mission. The exact surface composition and mineralogy is unknown, but measurements from prior missions Venera 13 and Vega 1 & 2 are consistent with alkali basalt and basalt, respectively, and orbital remote sensing is consistent with basaltic lava flows. Venus’s inferred volcanically active state also motivates the desire to understand the degassing behavior of a cooling Venus basalt, which could lend insight into the formation of the Venus atmosphere and surface mineralogy. Therefore, in order to further our knowledge of Venus’ surface mineralogy, this study focuses on two surface characterization aspects: 1)The oxidation and alteration behavior of a Venera 13 basalt with prolonged surface exposure, on the order of 2-3 days, and 2) The degassing of a cooling Venera 13 basalt representative of Venus’ crust. We explore the effect of fO2 and particle surface area on reaction rate by performing oxidation experiments using samples with a range of starting fO2and two different particle sizes exposed to a Venus atmosphere (e.g., a CO2(g)-N2(g)-SO2(g))at pressure-temperature conditions of the Venusian surface.