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Northern line-of-sight extinction within Gale Crater during the 2018 global dust storm was monitored daily using Mars Science Laboratory's Navcam. Additional observations with Mastcam (north) and Navcam (all directions) were obtained at a lower cadence. Using feature identification and georeferencing, extinction was estimated in all possible directions. Peak extinction of >1.1 km(-1) was measured between sols 2086 and 2090, an order of magnitude higher than previous maxima. Northern and western directions show an initial decrease, followed by a secondary peak in extinction, not seen in column opacity measurements. Due to foreground topography, eastern direction results are provided only as limits, and southern results were indeterminable. Mastcam red and green filter results agree well, but blue filter results show higher extinctions, likely due to low signal-to-noise. Morning results are systematically higher than afternoon results, potentially indicative of atmospheric mixing.

Plain Language Summary Once roughly every 3 Mars Years (5.5 Earth Years), Mars undergoes a dust storm so large it wraps around the planet, called a global dust storm. One of these storms occurred in 2018. The Curiosity Rover was able to operate throughout the storm and provided a unique view from the surface. During the 2018 storm, Curiosity obtained daily images which were used to measure how far the rover could see in one or more directions and, from that, monitor the dust within Gale Crater. At the peak of the storm, visibility was reduced to less than 3 km-for comparison, the crater rim, which sits approximately 30 km away, is visible at most times of year. In northern and western directions, visibility improved temporarily 15-20 Mars Days after the peak of the storm before worsening again and then slowly improving through to the end of the storm. Foreground features blocked sections in the east and south from view so only constraints could be placed on the eastern directions and nothing could be determined for the south. Morning visibility was worse than afternoon/evening visibility, which might be caused by atmospheric mixing processes.