From the early Greeks, to the early Romans, to Arostotle, to Capernicus, to Galileo, to Edwin Hubble, everyone has wondered how the Universe begins, how planets enter the Universe, and How did humans get here? Over the last century, more powerful telescopes and advanced supercomputers have led to more discoveries and knowledge about how the Universe formed as it is today, faster than before. Many astronomers accept that the Universe formed about 14 billion years ago due to a Big Bang, an explosion that also created protons, neutrons and electrons. This report will describe the five theories and processes involved in the formation of the solar system. Planets form by the process of new layers on top of existing ones. The pieces destined to become a planet gradually grow larger in a process known as accretion. Planetesimals and protoplanets are the main stages of how planets form. The process of planet formation is different for terrestrial planets and Jovian planets. Before the planetesimal stage, a process known as nebulae, both types of planets form from a cloud of gas and dust that collapses within a larger cloud. As gas and dust condense into rocky particles for terrestrial planets and icy particles for Jovian planets, the particles begin to collide with other particles of the same type to grow larger and accelerate growth as they orbit the sun. As soon as the particles are large enough, they are considered planetesimals. For terrestrial planets, gravity will eventually be unable to hold the planetesimals together once they reach the size that gravity can support, while for Jovian planets, gravity is strong enough to capture hydrogen and helium once the particle is big enough... ... middle of paper ...... Aperture Theory, Condensation Theory, Planetesimal Collision Theory, and Ejected Ring Theory. For the fission theory, astronomers believe that the Moon used to be attached to the Earth and somehow separated from the Earth. According to the Capture theory, the Moon is believed to have been created somewhere within the solar system and then, thanks to gravitational force, brought it closer to the Earth. This theory has no concrete evidence that this is how the Moon formed for the Earth. According to condensation theory, the Moon and Earth contracted together during the formation of the Solar System. For the theory of colliding planetesimals, the process is similar to that of the formation of terrestrial and Jovian planets. For the Ejected Ring theory, Mars is believed to have collided with Earth, leaving out a huge amount of matter which led to it condensing to form the Moon around Earth..