The Solar Nebular Disk Model theory (SNDM): The theory is that gravity caused the nebula to collapse and eventually started spinning. The accelerating rotation combined with gravity formed a disk. The disk's center heats up, creating our sun and the solar system. The planets are then formed by accumulating matter from rings in the disk.

1. Nebula begins to rotate

2. The speed of the spin increases and matter collapses

3. The gravitational collapse is much more efficient along the axis of the disk

Evidence:

• All the planets orbit in the same direction around the Sun and on the same plane

• All the inner planets are dense, rocky, low in mass, and high in density

• While the outer planets are less dense, gaseous, high in mass, and low in density

Early stages of a planet:

• Planetesimals

• Protoplanets

Planetesimals: Condensed material from the early stages of formation of the solar system. These small objects collide and merge to form a protoplanet.

Galaxy first planet: Jupiter

Many icy planetesimals merged, attracting more of the surrounding dust and gas. Other gas planets like Saturn would follow but would be smaller due to Jupiter having already collected more of the available material

In conclusion: Solar Nebular Disk Theory is the predominant theory for the origin of the Solar System. The gas and dust that formed our sun and the planets were rotating around the same axis. Gravity pulled together the matter and formed planetesimals and eventually planets

Kepler’s First Law

• The orbits of the planets are not a circle

• The planets’ orbits are actually an ellipse and the Sun is located at a focus point

• Focus points are not the center of the orbit (they're off to the side)

Kepler's second law:

• The planet moves faster when close to the Sun and slower when away from the Sun

In conclusion:

• Kepler’s first law states that the orbits are actually ellipses

• Kepler’s second law states that the planets move faster when close to the Sun