Solar variability as a factor in planetary change

A theory is presented which accounts for the composition of the moon, the high density of Mercury and the absence of water on Venus. It envisages the sun as being older than the currently accepted age of 4.5-5.0 billion years. Available information is consistent with an episode of increased luminosity in a pre-existing sun accompanied by planets ancestral to the present ones. The result was widespread melting and vaporization of material in the inner solar system. The crust and outer mantle of Mercury was vaporized and driven out into space where it recondensed. Part of this material accreted into a body that was to become the earth's moon; part of it formed planetesimals which impacted on the inner planets to produce craters that are still in evidence on the moon, Mars and Mercury. Venus is seen as having once possessed substantial quantities of water which were driven away by the heat. Some loss of water might also have occurred from the earth, but it would not have been as complete due to its greater distance from the sun. The present CO2 atmosphere of Venus resulted from thermal decomposition of carbonate rocks in the crust. (Auth.)