Dust ring/torus around Mars,waiting for detection by NOZOMI

Two small satellites of Mars, Phobos and Deimos, can be dust sources around Mars. Orbits of circummartian dust particles are controlled by solar radiation pressure as well as Martian oblateness. Their orbital eccentricity and inclination can be enhanced greatly by the orbital resonance. Particles from Phobos would form a thin dust ring where dust radius is dominant in 20–200μm. On the other hand, particles from Deimos would form an extended dust torus. Collisions of ring particles on Phobos and Deimos may be the most important dust source. The upper limit of dust production from this self-sustaining mechanism can be estimated from the erosion rate of Phobos. Japanese Mars mission NOZOMI (PLANET-B) could discover dust ring/torus through direct detection by MDC (Mars Dust Counter).