What can’t be photographed

The photographs sent back to earth from Mars have a kind of “signature,” something that both acknowledges the colossal technical achievement of the mission and clearly signals its photographic limits. In particular, many of the images released by NASA are composites or mosaics. These usually depict an “object” (a crater, a landscape, a dust storm) that can be named in human language, and could, in principle, be seen by a human being, but that can’t actually be photographed. This montage look, showing the crisp boundaries of a number of photographic images joined together, refers to the object and conveys some things about it, but simultaneously acknowledges that this is radically unlike human vision.