Martian moon Deimos appears dark, framed by the brighter planet Mars behind it, in this visible light monochromatic Asteroid Framing Camera image, acquired by ESA’s Hera spacecraft during its gravity-assist flyby on 12 March 2025. The car-sized planetary defence spacecraft was approximately 1000 km from the 12.4-km-diameter Deimos moon when this image was acquired. Deimos orbits approximately 23 500 km from the surface of Mars and is tidally locked, so that this side of the dark moon is rarely seen. At the top of the image is the bright Terra Sabaea region, close to the martian equator, outlined by darker regions about it, with part of the 450 km-diameter Huygen crater seen to the right side of the image. To the bottom right corner is part of Hellas Basin, among the largest known impact craters in the Solar System with a diameter of 2300 km and a depth of more than 7 km. Hera’s 1020x1020 pixel Asteroid Framing Camera is employed for both navigation and scientific investigation.