1. Gravitational Collapse: The nebula was incredibly vast and contained mostly hydrogen and helium. Over millions of years, tiny variations in density caused some regions to have slightly more gravity. This slight imbalance pulled in more material, causing the denser region to grow even larger and more massive.
2. Rotation and Heating: As more material was pulled in, the region started to rotate faster, similar to a spinning ice skater pulling their arms in. This rotation flattened the cloud into a disk. The gravitational pressure also squeezed the material together, causing it to heat up.
3. Nuclear Fusion: Eventually, the core of the collapsing cloud became so hot and dense that nuclear fusion started to occur. This is the process where hydrogen atoms fuse together to form helium, releasing immense amounts of energy. This energy output is what powers the Sun and gives it its light and heat.
4. Stable Star: The outward pressure from the nuclear fusion balances the inward pull of gravity, creating a stable star. This equilibrium is what allows the Sun to burn steadily for billions of years.
In summary: The Sun was formed from a giant cloud of gas and dust that collapsed under its own gravity, leading to nuclear fusion in its core. This process continues to this day, providing the energy that sustains life on Earth.
