Vega and Giotto missions: is there an invisible mass in the Solar system

One can expect the presence of invisible mass (in the form of cometary nuclei) at the heliocentric distances 2x103 <or approx. r <or approx 2x104 a.u. if one assumes that the Oort cloud being only a rarefied halo surrounding the core (dense inner cometary cloud) and the mass of the comet Halley being typical for comets both in the core and the Oort cloud populations. The mass appears to be M ∼ 0.03 Msun with the angular momentum of the order of 1053 gcm2/s. This mass value is of the order of the total mass of the planetary system before the loss of volatiles. Therefore during of the protosolar nebula evolution of the formation of comets and planets was spent approximately equal masses