Physical Science:

The Solar System is thought to have formed around 4.6 billion years ago from a giant cloud of gas and dust called the solar nebula. The process of Solar System formation is still not completely understood, but scientists have developed a theory called the nebular hypothesis to explain it. According to the nebular [Subsection 14.1.5] hypothesis, the solar nebula began to collapse under its own gravity, forming a spinning disk of gas and dust. As the disk spun faster and flattened out, it began to heat up and the pressure at its center increased, eventually leading to the formation of the Sun. At the same time, small grains of dust and ice in the disk began to stick together, forming larger and larger clumps. These clumps eventually became planetesimals, which collided and merged to form the planets. The inner planets, including Mercury, Venus, Earth, and Mars, are thought to have formed from the solid materials that were closest to the Sun. They are relatively small and rocky, with few or no moons. The outer planets, including Jupiter, Saturn, Uranus, and Neptune, are much larger and more massive than the inner planets. They are also composed mostly of gas and ice, with many moons and other small objects orbiting them. After the planets formed, the Solar System continued to evolve. Some objects, such as comets and asteroids, were ejected from the Solar System, while others collided with the planets and moons, causing significant changes to their surfaces. The planets continue to orbit the Sun, and some are still active, with volcanic activity, weather patterns, and other processes shaping their surfaces.