THE EFFECT OF RADIATION ON THE MOTION OF METEOROIDS

摘要

It has been known for over a century that radiation pressure exerts a force on small particles in the direction of the radiation flow. It has also been recognised for a similar time that when this radiation is absorbed and re-emitted, this can generate a drag with a component also in the transverse direction. The principle that governs these forces is easy to state, namely that the radiation must be considered in the rest-frame of the emitting surface. Generating actual expressions has proved harder in anything but the simplest situations. We review the development of the subject. In terms of orbital evolution of interplanetary matter, these effects can be important, but again deriving analytical expressions for the rate of change of the orbital elements is difficult. We will also review the derivation and derived solutions of these equations. Finally, we will consider their application to the orbital evolution of small grains, paying particular attention to their effect on dust ejected from asteroids and comets, the normal formation mechanism for meteoroid streams. These streams are responsible for the observed meteor showers, caused when the Earth passes through such a stream.