MISSING MASS IN, OR FROM THE SOLAR SYSTEM?

摘要

Does the Solar System contain missing mass or was it the source of massive "objects" that have now moved to other regions of the Galaxy where they are undetectable ? Stars shine and planets merely reflect. The cross-sectional-area-to-mass ratio, A/M is important in the latter context; A/M is small in the case of planet-sized objects and these do not have to be moved far from the Sun before they become visually undetectable with present Earth-based telescopes. As one moves to asteroids and cometary nuclei A/M increases and it becomes very large for dust. Dust is unmissable. The term 'moved far' is important. The dynamics of the solar system is such that the scattering of dust and cometary nuclei throughout the galactic disc is easily accomplished. Asteroids can be scattered throughout the Solar System. But the growth of planets requires the pre-planetary aggregates to be on low-eccentricity orbits and this precludes the escape of planets from the solar potential well, The Solar System does produce some missing mass. But not much, and certainly not enough.