These animations shows three views of the Martian moon Phobos as viewed by the Mars Odyssey orbiter. The apparent motion is due to movement by Odyssey’s camera, Thermal Emission Imaging System (THEMIS) rather than moon.
Each of the three panels is a series of images taken on different dates (from top to bottom): 29 September, 2017; 15 February, 2018; and 24 April, 2019. Deimos, Mars’ other moon, can also be seen in the second panel. These are visible light images, but THEMIS is mainly used for thermal-infrared scans.
Image Credit: NASA