The Lifetime and Renewal of Comets

A brief review is conducted of some of the more well-known comets detected in the solar system. The measured attrition rates of Halley\u27s and other comets are used to project a rigorous calculation of their anticipated lifetimes. Some backward projections are made to provide estimates of reasonable upper limits on their current ages. Some postulated theories for the replenishment of the comet inventory from the assumed Oort Cloud are assessed together with proposed schemes for solar capture of their orbits. Orbital mechanics is used to evaluate the probability of the validity of these theories