A theory is hereby proposed that an unknown mega-massive planet has, for billions of years, been orbiting at 77.2 AU from the sun -- within a 44 AU-wide, virtually empty Great Void that surrounds the Kuiper Belt (One AU = 93 million miles, the mean Earth-Sun distance). The Void is postulated to have been formed by strong gravitational attraction of the unknown planet having removed all CKBOs (Classical Kuiper Belt Objects) that had existed previously in the vicinity of the massive planet's huge orbit... The 77.2 AU distance from the sun of the proposed unknown planet is derived from a...