Scientific Observations With the InSight Solar Arrays: Dust, Clouds, and Eclipses on Mars

• Published in: Earth and space science (Hoboken, N.J.) Vol. 7; no. 5; pp. e2019EA000992 - n/a
• Main Authors: Lorenz, Ralph D., Lemmon, Mark T., Maki, Justin, Banfield, Donald, Spiga, Aymeric, Charalambous, Constantinos, Barrett, Elizabeth, Herman, Jennifer A., White, Brett T., Pasco, Samuel, Banerdt, W. Bruce
• Format: Journal Article
• Language: English
• Published: United States John Wiley & Sons, Inc 01-05-2020; American Geophysical Union/Wiley; John Wiley and Sons Inc; American Geophysical Union (AGU)
• Subjects: Archives & records; Arrays; Atmosphere; Atmospheres; Atmospheric Composition and Structure; Boundary layers; Cameras; Carbon dioxide; Clouds; Dust; Earth Sciences; eclipses; Engineering; InSight at Mars; Instruments and Techniques; Mars; Meteorology; Planetary Atmospheres; Planetary Atmospheres, Clouds, and Hazes; Planetary Sciences: Astrobiology; Planetary Sciences: Fluid Planets; Planetary Sciences: Solar System Objects; Planetary Sciences: Solid Surface Planets; Radiation: Transmission and Scattering; Sciences of the Universe; Solar energy; Solar panels; sunlight; Telemetry; Mars; sunlight; clouds; eclipses; dust
• ISSN: 2333-5084; 2333-5084
• DOI: 10.1029/2019EA000992

Records of solar array currents recorded by the InSight lander during its first 200 sols on Mars are presented. In addition to the geometric variation in illumination on seasonal and diurnal timescales, the data are influenced by dust suspended in the atmosphere and deposited on the solar panels. Although no dust devils have been detected by InSight's cameras, brief excursions in solar array currents suggest that at least some of the vortices detected by transient pressure drops are accompanied by dust. A step increase in array output (i.e., a “cleaning event”) was observed to be directly associated with the passage of a strong vortex. Some quasiperiodic variations in solar array current are suggestive of dust variations in the planetary boundary layer. Nonzero array outputs before sunrise and after sunset are indicative of scattering in the atmosphere: A notable increase in evening twilight currents is observed associated with noctilucent clouds, likely of water or carbon dioxide ice. Finally, although the observations are intermittent (typically a few hours per sol) and at a modest sample rate (one to two samples per minute), three single‐sample light dips are seen associated with Phobos eclipses. These results demonstrate that engineering data from solar arrays provide valuable scientific situational awareness of the Martian environment.
Key Points
Solar array current telemetry gives situational awareness of the Mars surface environment
Dust in the atmosphere is observed to vary
Twilight currents indicate clouds