A Solar System is Born Chapter 10 Section 2

After the Big Bang rocks and gases begin moving around each other. *Nebulas are mixtures of gas and dust. *The outward pressure balances with the inner gravitational pull to keep a Nebula from collapsing.

*The center of the collapsed Nebula would become very dense and hot. *Over time, the nebula will become flattened into a rotating disk.

Planetesimals In a solar nebula, bits of dust collided and stuck together to form small bodies. The largest of these colliding bodies are called planetesimals, or small bodies.

Gas Giants The largest planetisimals were far enough away from the solar nebula to attract nebula gases. *The planets J,S, U, N are known to be gas giants.

The Sun is Born When the gas in the nebula’s center stopped collapsing, our Sun was born.

*Birth of a Planet, in order: 1. The solar nebula began to collapse. 2. The solar nebula rotates and flattens. It grow warmer near its center. 3. Planetesimals begin to form. 4. The largest of the Planetesimals grow in size and attract more gas and dust. 5. Planets begin to grow as planetismals and collide with one another. 6. The sun is born. The remaining gas and dust are removed from the solar system.

Inner Planets *The inner planets of our solar system are mostly rocky. They are M,V,E,M. After the planets were formed, the center mass of the solar nebula became so dense and hot it formed Helium.