Richard A.F. Grieve
As we go about daily living, we are reminded in many ways that we do not exist in isolation. We are part of a much larger symbiotic system of life on earth and it is even popular these days to talk of the earth as if it were a single, closed system. The earth, however, does not exist in isolation.
It is a planet in the solar system and, as such, is subjected to solar system processes. One such process is the impact of interplanetary asteroids and comets.
