A Search for Resonant Structures in the Zodiacal Cloud with COBE DIRBE: The Mars Wake and Jupiter’s Trojan Clouds

We searched the COBE DIRBE Sky and Zodi Atlas for a wake of dust trailing Mars and for Trojan dust near Jupiter’s L5 Lagrange point. We compare the DIRBE images to a model Mars wake based on the empirical model of the Earth’s wake as seen by the DIRBE and place a 3-σ upper limit on the fractional overdensity of particles in the Mars wake of 18% of the fractional overdensity trailing the Earth. We place a 3-σ upper limit on the effective emitting area of large (10-100 micron diameter) particles trapped at Jupiter’s L5 Lagrange point of 6× 10 cm, assuming that these large dust grains are distributed in space like the Trojan asteroids. We would have detected the Mars wake if the surface area of dust in the wake scaled simply as the mass of the planet times the Poynting-Robertson time scale. Subject headings: asteroids – extrasolar planets – interplanetary dust – Jupiter – Mars – resonances Alfred P. Sloan Research Fellow