In 1995 Richard Muller et al proposed the existance of a twin star of the sun, Nemesis. This would expain the cyclic mass extinctions. To date there seems to be little substantiation for the existance of Nemesis and the only remaining option is: find it. That may be happening here: http://newfrontiersinscience.com/Members/v02n01/a/NFS0201a.shtml#fnB2 Apparantly the precession of the Equinoxes is not caused by gravity of the sun and moon but by the orbit of the sun in space, as it must be influenced by a twin star. Is this Nemesis? And can we calculate it's position from the apparant precession?