An analytical model for the mass distribution of the interplanetary dust cloud Original Research Article

The mass dependence of the number density distribution for the interplanetary dust particles is discussed taking into account the particlesʹ collisional process. From analytical estimations, it is found that the interplanetary dust cloud has two typical shapes of its number density distribution for particles with masses larger than 10−12g. Moreover, the radial dependence of the dust production rate by particlesʹ parent bodies plays an important role to determine the slope of the number density distribution. To explain the interplanetary dust flux modeled at 1AU, the direct dust supply at 1AU from the parent bodies is necessary. This evidence suggests that particles produced from comets are dominant in the interplanetary dust flux at 1AU, i.e. a mass ratio of the cometary dust to the asteroidal dust is 2:1.