Abstract Phobos is the first asteroid-like body to be observed at close range: during the Viking mission, several close fly-bys made possible extensive mapping of its surface at resolutions down to a few m. During the Phobos mission, two encounters at a distance of about 200 km were performed before the premature termination of the mission, on March 28th 1989. The images from the camera system (FREGAT) complement the Viking coverage, improving upon it for about 25% of the surface. The KRFM/ISM infrared complex obtained two tracks across the equatorial region, and (for ISM) a 25 × 25 pixels image, with a pixel size of .7 km. They provide the first spatially resolved data on a small solar system body in the infrared spectral range. The surface of Phobos is found to be markedly heterogeneous at a km scale. This is surprising given the expected high efficiency of lateral transport processes on the surface of Phobos. During the next decade, several main belt asteroids will be observed with similar resolutions during the GALILEO, C.R.A.F and CASSINI missions. This comparison will be essential for unravelling the relationship between Phobos and small main belt asteroids, and for understanding the specific aspects of surface evolution on a close planetary satellite.