In May 1977 a planet-wide control net of Mars was computed by means of a large single-block analytical triangulation using 17,224 measurements of 3037 control points on 928 Mariner 9 pictures. Areographic coordinates of the control points are available on microfiche (see Table 2). The direction of the spin axis and the rotation rate as determined by Viking were used. The angle V, measured from Mars' vernal equinox along the equator to the prime meridian (Airy-0), was found to be V=148.37¿+350.891986¿ (J.D. 2,433,282.5).