关于这张图
NASA's Ingenuity Mars Helicopter took these images on its fourth flight, on April 30, 2021, using its navigation camera. The camera, which tracks surface features below the helicopter, takes images at a rate at which the helicopter's blades appear frozen in place, despite making 21 full rotations in-between each image. In flight, the blades spin at 2,537 rpm. The images are aligned entirely using Ingenuity's on-board position tracking system highlighting the stability and accuracy of the navigation algorithm. Movie available at https://photojournal.jpl.nasa.gov/catalog/PIA24630
