An article published in the journal “Science” reports a study that offers an explanation for the structure of the solar system with the different characteristics of the inner rocky planets and the outer gas planets. A team of researchers led by Dr. Tim Lichtenberg of the British University of Oxford put together information on other star systems in their formation phase and on the contents of meteorites to create simulations of the origin of the solar system. The conclusion is that it occurred in two phases, first the rocky planets and then the gas planets.