​Quick Review

Let us see if you can still remember what we have discussed last week.​

Prior Idea

As early as 5th century, philosophers gave us the idea that there is a central fire (sun) and are orbited by densed materials.

Nebular Hypothesis

This theory states that as gas swirled around, group of gasses caused the formation of the sun and planets.

Nebula

It is a cloud of gas and dust found in space. The existing gases in the nebula are hydrogen and helium, while dust particles are mainly composed of carbon and iron.This theory states that as gas swirled around, group of gasses caused the formation of the sun and planets.

To be a True planet…​

1. The object must be orbiting the sun.

2. It should be nearly spherical.

3. It should be large enough to clear all matter from its orbital zone.​

​Planetary Motion

ROTATION – the spin on it’s axis or the change of daytime to nighttime on Earth

REVOLUTION – the period of completion of a planet’s journey around the sun.

Orbit – definite path where planet can move around.​

​URANUS

• The seventh planet from the Sun with the third largest diameter in our solar system, Uranus is very cold and windy.

• ​The ice giant is surrounded by 13 faint rings and 27 small moons as it rotates at a nearly 90-degree angle from the plane of its orbit. This unique tilt makes Uranus appear to spin on its side, orbiting the Sun like a rolling ball.

​Example