** Or, more precisely, about 2 x 10<sup>9</sup> years ago, according to "Lunar nodal tide and distance to the Moon during the Precambrian", J.C.G. Walker, K.J. Zahnle - Nature, 1986. There may be other theories (even negating this); I found that using Google Academic with "tidal friction earth moon collision". [[User:Sunda62|Sunda62]] 13:36, 29 September 2010 (EDT) | ** Or, more precisely, about 2 x 10<sup>9</sup> years ago, according to "Lunar nodal tide and distance to the Moon during the Precambrian", J.C.G. Walker, K.J. Zahnle - Nature, 1986. There may be other theories (even negating this); I found that using Google Academic with "tidal friction earth moon collision". [[User:Sunda62|Sunda62]] 13:36, 29 September 2010 (EDT) |