How Did the Solar System Form?
How did the solar system form? During the formation of our solar system, tiny dust particles orbited the infant Sun in a nearly circular orbit. The collisions that formed these first solid objects allowed them to stick together and grow to hundreds of meters. Eventually, these flakes collided with other solid particles, forming larger planetesimals that accreted to form the planets we know today.
The formation of planets was further facilitated by the differences in temperatures. The inner solar nebula was hot and had few gases and ices, whereas the outer nebula contained ices and gasses of a higher temperature. As a result, the planets were formed with a rocky composition. And as a result of this rocky composition, the icy moons are so far the largest.
To date, there are two main theories regarding how the solar system formed. One is that it originated from a solar nebula, a cloud of gas and dust. A nearby supernova explosion probably initiated this collapse. After that, the gas and dust that formed the planets were squeezed out by the pressure of light. In addition, the planets contributed to the cleaning process by absorbing planetesimals. Other theories say that a large impact caused the axis tilt of Uranus. And a similar theory suggests that the Earth was hit by a Mars-sized object. This debris eventually coalesced to form the Moon.
The formation of the outer planets took place in a similar way to that of the Earth. In fact, these planets had similar histories and polar deposits. The latter were shaped by comets, which were then swept up by the massive planets’ gravity fields. The remainder of the material was eventually blown away, and the moon and other outer planets are now entirely ice-capped. And yet, they still maintain icy polar caps.
The formation of the solar system is the result of several processes that began 4.57 billion years ago. The Sun was a dense cloud of gas and dust. Something caused this cloud to collapse, possibly a supernova or passing star. This collapse was accelerated by several processes. The material in the center of the cloud became more dense and the temperature increased, and it then began nuclear fusion. After 50 million years, the protostar became a star.
After billions of years of accretion and clean-up, planets formed. They were created when the protostar became hot enough to form a star. The planets’ surfaces and atmospheres may be significantly modified by their interaction with each other. Earth’s water came from comets, while Venus and Uranus tilt and rotate. And, as the protostar was formed, it collapsed into a rapidly rotating disk. The increasing temperatures caused the nebula to vaporize most of the solid material.
As the disk neared the Sun, the temperature inside it cooled. Some objects grew big enough to be shaped by gravity, but other pieces remained. The larger objects were sculpted into planets, while smaller leftovers dissolved into asteroids and meteoroids. Finally, the gas inside the disk eventually cooled and turned into silicates, metals, and small irregular moons. But the process did not end there.