Animation - Mars's moon Deimos crosses the surface of Mars in this sequence of TIRI images
Animation - Mars's moon Deimos crosses the surface of Mars in this sequence of TIRI images
Martian moon Deimos seen crossing the face of Mars in this sequence of Thermal Infrared Imager images acquired during the Hera mission’s 12 March 2025 gravity-assist flyby of Mars.
The car-sized Hera spacecraft was about 1000 kilometres away from Hera as these images were acquired. Deimos orbits at approximately 23,500 kilometres from the surface of Mars and is tidally locked, so that this side of the moon is rarely seen.
Hera's TIRI – supplied to the mission by the Japan Aerospace Exploration Agency, JAXA – sees in mid-infrared spectral bands to chart surface temperature. Because Deimos lacks an atmosphere, the side of the moon being illuminated by the Sun is considerably warmer than the planet beneath it.
