The Coherent Catastrophism Hypothesis
by
Duncan Steel
Joule Physics Laboratory, University of Salford, UK

The fundamental concept of the hypothesis of coherent catastrophism is that the environment in the inner solar system (and, in consequence, on Earth) is subject to occasional gross deviations from the long-term norm due to the arrival of giant comets which, when trapped in cis-jovian orbits and disintegrated into myriad fragments of varying size, produce an epoch of greatly-enhanced impact hazard for life on our planet. The large increase in the dust flux to the upper atmosphere can also cause severe climatic perturbations. Such events may be expected to occur about once every 100 kyr (based on the population of Centaurs in the outer solar system and their orbital instability), and to persist for a few times 10 kyr. Further, it is suggested that we are currently experiencing the tail-end of such an event, which began circa 30 kyr ago with the capture of a giant comet of which Comet Encke is the best-known active daughter fragment at present.

Date received: March 5, 2002