The phase curves (whole-disk brightness vs. solar phase angle) of the Martian satellites were compiled out to 125¿ phase angle from ground-based and spacecraft photometric observations. The data were modeled with the Lumme-Bowell theory. Accurate phase integrals, zero-phase geometric albedos and Bond albedos were obtained from the best fit theoretical curves. The microstructural and particulate surface properties of Phobos differ little from those of Deimos. The satellites' very similar whole-body densities and geochemical and microphysical makeup suggest a common origin. However, having spent a considerable portion of their lifetimes in proximity to Mars probably did modify their surface characteristics. The value of the surface roughness (less than that on an asteroid of comparable size), the debris mantle on Deimos and the grooves on Phobos are probably evidence of such modifications. Consequently, Phobos and Deimos should be used as models of asteroid-class objects only with reservations.