The Origin of the Solar System

The Origin of the Solar System

The Solar Nebula Theory

• The Solar Nebula Theory posits that the solar system originated from a rotating disc of dust and gas known as a solar nebula.
• This nebula was part of a remnant cloud of material left over from the formation of the Milky Way galaxy.
• As the nebula collapsed under its own gravity, it spun faster and flattered into the disc shape, with the majority of material pulled towards the centre.

Formation of the Sun

• At the centre of the nebula, the intense pressure and temperature gave birth to our Sun through the process of nuclear fusion.
• This process involves the fusion of hydrogen nuclei into helium, releasing a tremendous amount of energy.

Formation of Planets

• Meanwhile, solid particles in the disc began to collide and stick together in a process called accretion.
• These formed planetesimals, and eventually, through more collisions and accretions, they became protoplanets.
• These protoplanets ultimately became the planets as we know them, with lighter materials forming the gas and ice giants further from the Sun, and denser materials forming the terrestrial planets closer to the Sun.

Asteroids and Comets

• Leftover materials that didn’t form into planets resulted in other bodies such as asteroids and comets.
• Asteroids are more common in the inner solar system, whereas comets are often found in the outer solar system.