Solar System

The Sun, the planets and all other bodies that orbit the Sun.

Formation explained by The Solar Nebula Theory.

Solar Nebula Theory

Theory that explains the formation of our solar system.

1. Nebula collapses
2. Spins into disc
3. Accretion of gas and dust forms Planets & moons
4. Heavy bombardment leads to tilt of some planets and craters
5. Solar wind pushes out left over gas and dust

Accretion

Process of dust and gas sticking together

This is how planets form

Gas and Dust -> Planetessimals -> Planets

Terrestrial

Close to sun

Types of planets which are small and rocky

More dense, heavier

Jovian

Far from Sun

Types of planets which are larger and made up of gas

Less dense, lighter

Kepler's First Law of Planetary Motion

Shape of Orbit

Planets travel around the Sun on a path that is the shape of an ellipse.  An ellipse is an oval.

This means that the distance between the planet and the Sun is not always the same.

Sometimes closer, sometimes further away

Kepler's Second Law of Planetary Motion

Speed of Orbit

Planets do not travel at a constant speed

When a planet is closer to the Sun it travels faster

When a planet is far from the Sun it travels slower

Orbital Terms

Orbit - path an object follows around the Sun

Aphelion - farthest point Away from the Sun

Perihelion - closest point to the Sun

Gravity

Force of attraction that keeps the planets in orbit around the sun.

More of this = closer = faster

Less of this = further away = slower

Kepler's Third Law of Planetary Motion

Length of Year (time to get around the Sun once)

The closer a planet is to the Sun, the shorter its year

The further a planet is from the Sun, the longer its year