Perseverance MEDA Atmospheric Pressure Observations—Initial Results

Abstract

The Mars2020 Perseverance Rover landed successfully on the Martian surface on the Jezero Crater floor (18.44°N, 77.45°E) at Martian solar longitude, Ls, ∼5° in February 2021. Since then, it has produced highly valuable environmental measurements with a versatile scientific payload including the MEDA (Mars Environmental Dynamics Analyzer) suite of environmental sensors. One of the MEDA systems is the PS pressure sensor system, which weighs 40 g and has an estimated absolute accuracy of better than 3.5 Pa and a resolution of 0.13 Pa. We present initial results from the first 414 sols of Martian atmospheric surface pressure observations by the PS, whose performance was found to meet its specifications. Observed sol-averaged atmospheric pressures follow an anticipated pattern of pressure variation in the course of the advancing season and are consistent with data from other landing missions. The observed daily pressure amplitude varies by ∼2%–5 % of the sol-averaged pressure, with absolute amplitude 10–35 Pa in an approximately direct relationship with airborne dust. During a regional dust storm, which began at Ls ∼ 135°, the daily pressure amplitude roughly doubled. The daily pressure variations were found to be remarkably sensitive to the seasonal evolution of the atmosphere. In particular, analysis of the daily pressure signature revealed diagnostic information likely related to the regional scale structure of the atmosphere. Comparison of Perseverance pressure observations with data from other landers reveals the global scale seasonal behavior of Mars' atmosphere.