At http://cosmictusk.com/rare-bill-napier-essay-giant-comets-messengers-of-life-and-death.html … an article by Bill Napier can be read on the Cosmic Tusk web site which was published in ‘God, the Universe and Man – Why do we exist?’, Patrus, Dusseldorf: 2003 (original in Deutsche). In a nutshell the article associates the origins of religion in the Neolithic era to a recurrent giant comet that manifested itself in the night sky – the earth regularly encountering an associated meteor shower of ‘huge intensity’. One sentence reads, ‘the prospect that cosmic myths, megaliths, and art dating from this time may have been response on the ground to threats in the sky has in recent years moved from Velikovskian fancy to a subject for serious scholarly discussion’. Catastrophic models involving comets went out of fashion in the 19th century as a result of uniformitarian arguments. Geologists realised the terrestrial landscape had been formed over aeons by gradual processes – and astronomy played it’s part too, he added. Comets lost their bad aura when it was realised they ended up as just a swarm of dust. In the 20th century catastrophism became the domain of cranks but in the latter decades wide angle telescopic images of the sky revealed the existence of small earth crossing asteroids and the prospect of encounters with earth in the past suddenly became a revived possibility. Next, impact craters began to be found on the surface – often overlain by sediments or unrecognised as geologists had simply not been looking for them. It emerged that the earth was regularly bombarded in the past and such evidence could not readily be ignored … and so on.
In an additional comment on the web site, to a query made by EP Grondine, Bill Napier said of the WISE mission, a population of dark earth crossing comets, undetectable visually, would be bright in the infrared instruments on the satellite. However, such dark bodies spend the great bulk of their orbit beyond Mars and not within range of the WISE satellite. On that basis it would take centuries to map them out fully even with infrared telescopes. Some other comet fragments are too small to be seen easily but are capable of packing a collective punch. Next generation Large Synoptic Survey Telescopes may reveal more of the material out there in near space – but only if they run for long enough.