The VEGA and Giotto missions - Is there an invisible mass in the solar system?

One can expect the presence of an invisible mass (in the form of cometary nuclei) at the heliocentric distances 2×10³ ⪉ r ⪉ 2×10⁴a.u. if one assumes 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 M_sun; with an angular momentum of the order of 10⁵³g cm²/s. This mass value is of the order of the total mass of the planetary system before the loss of volatiles. Therefore during the protosolar nebula evolution approximately equal masses were spent on the formation of comets and planets.