Hello LostinSpace,
It's a difficult question to answer. The trigger mechanism that resulted in the axial tilt(s) of the Earth in former times could stem from any number of possible agents. It is generally believed in science that the equatorial bulge of the Earth acts to stabilise its axis and that to effect any change in its rotational axis would require a collision with a body so large that it would effectively vaporize all life on the planet. The work of Dr F. Barbiero, however, deomonstrates how a relatively small asteroid striking one of the Earth's oceans can alter the axis. Whilst such an event would be truly catastrophic, it would not be the extinction level event that is generally supposed. My forthcoming book presents evidence from a variety of sources of a pole shift in relatively recent historical times.
Best wishes,
Scott Creighton
edit on 25/11/2011 by Scott Creighton because: Fix typo.
