He is from the contraction of this protoestrela that the set free material will give origin, for process of shocks and lesser particle capture for bigger bodies, to the planetary systems, as our Solar System. The structural evolution of the Planet Land our system occupies strategical position in the Way Lctea, being situated enters the edge and its center, where little harmful radiation and little comet clouds penetrate in its interior. If next to the center to the galaxy, it would be reached by fort harmful radiation, or for comets and if next its edge would not exist the elements heavy that gave conditions to the development of the planet that we inhabit, with conseguinte impossibility of the sprouting and existence of the life. The Planet Land is studied using of a division and subdivision inside of a time scale: ons, the ages, the periods, times and the ages. on is an interval of very great time. They are considered four ons: hadeano, archean, proterozico and fanerozico; Age is an interval of lesser time that one on and that considers as the oceans and the continents were made use and still which was the beings that inhabited the planet; Period is a division of the age; Time is a subdivision of a period; Age is the subdivision of a time, corresponds to a time interval that goes of one the six million years. Comment: nor all the ages obey these subdivises in periods, times and ages. In the presented table ahead this division could better be understood.