How The Life Begin

Subsequent evolution The planets were originally thought to have formed in or near their current orbits. From that, a minimum mass of the nebula i.e. the protoplanetary disc was derived that was necessary to form the planets – the minimum mass solar nebula. It was derived that the nebula mass must have exceeded 3585 times that of the Earth. However, this has been questioned during the last 20 years. Currently, many planetary scientists think that the Solar System might have looked very different after its initial formation: several objects at least as massive as Mercury were present in the inner Solar System, the outer Solar System was much more compact than it is now, and the  Kuiper belt  was much closer to the Sun. Terrestrial planets At the end of the planetary formation epoch, the inner Solar System was populated by 50–100 Moon- to Mars-sized  planetary embryos . Further growth was possible only because these bodies collided and merged, which took les...

Formation and evolution of the Solar System Jump to navigation Jump to search Artist's conception of a  protoplanetary disk The formation and evolution of the  Solar System  began 4.6  billion years ago  with the  gravitational collapse  of a small part of a giant  molecular cloud . [1]  Most of the collapsing mass collected in the center, forming the  Sun , while the rest flattened into a  protoplanetary disk  out of which the  planets ,  moons ,  asteroids , and other  small Solar System bodies formed. This model, known as the  nebular hypothesis  was first developed in the 18th century by  Emanuel Swedenborg ,  Immanuel Kant , and  Pierre-Simon Laplace . Its subsequent development has interwoven a variety of scientific disciplines including  astronomy ,  physics ,  geology , and  planetary science . Since the dawn of the  space age ...