[ICR Creation Online] It is claimed that prevailing theories of Solar System formation cannot account for the lack of hydrogen and helium in the planets Mercury, Venus, Earth, and Mars. The simple answer is that these light gases were in fact present when the terrestrial planets were formed, but they escaped into space for two reasons. The first reason is that the terrestrial planets are closer to the Sun, and the higher temperatures made the light gases more energetic, and therefore more likely to escape. The second reason is that these four planets are smaller than the outer gas giants, and therefore they did not have enough gravity to hold on to these energetic light gases.