Cometary and Asteroidal Source Fractions in the Zodiacal Cloud Mass Budget

This paper examines Fraction of the cloud supply attributable to Jupiter-family comets versus asteroids, tested against the total resupply requirement. Using only published input values and transparent formulae, the calculation obtains the following headline results: required_resupply_kg_s = 850; jfc_supply_kg_s = 700; asteroidal_supply_kg_s = 120; jfc_fraction_percent = 82.4; asteroidal_fraction_percent = 14.1; combined_supply_to_required_ratio = 1. Jupiter-family comets supply roughly four fifths of the required input in the central budget, with asteroid collisions contributing most of the remainder; an asteroid-only cloud falls short of the requirement by a large factor. The method, inputs and limitations are stated in full so that any reader can reproduce or rescale every number from the deposited calculation script. Agreement and disagreement with independent published estimates are reported at their actual size, and the conclusions are limited to what the budget arithmetic supports.