Four billion years ago is an awfully long time to speculate about. Whereas, Velikovsky thought Saturn was a captured Brown Dwarf with Venus as one of its planets. He also thought that Uranus was turned on its side by a close passage of Saturn on its way in... His opinion is rather less than scientifically proven, but intersting nevertheless. By the way, he also predicted most of the moons of Jupiter and Saturn would be composed of water ice. As I mentioned earlier, four billion years is an awfully long time to speculate about and since anything can happen and usually does happen, why not speculate? By the way, I am NOT a proponent of Velikovsky's ideas but bring up the point, just because.