关于这张图
This image is from an animation that shows the evolution of the 2018 Mars global dust storm from late May to September. The animation shows the optical depth tau -- a measure of how much light is being blocked by atmospheric dust as measured by the Mars Climate Sounder instrument onboard NASA's Mars Reconnaissance Orbiter. NASA's Opportunity rover is marked with a red dot. The dust is mapped to two opposite hemispheres of Mars, giving a view of the full globe. Certain features of the Martian terrain, including Olympus Mons, the three volcanoes in the equatorial region, and Vallis Marineris, a…