Hmm. Interesting date they calculated. June 29th 3123 BC. Tunguska Event, June 30th 1908 AD. I've read hypothosis that Earth crosses the orbit of Comet Encke around that time every year. Could it have been a Tunguska type of event? I find the .5 km asteroid unlikley, that is a geological tick of the clock, a crater left by an asteroid that size would still be visable.
|