Shape of the Earth

Shape of the Earth

The story of an Oblate Spheroid

An Oblate Spheroid

• The Earth on the left is what we think of when we think of Earth's shape

• It isn't though.

• The Earth is a slightly flattened sphere, wider than it is tall.

• We call this an Oblate Spheroid

Multiple Choice

An Oblate Spheroid is

• taller than it is wide

• wider than it is tall

• perfectly round

Earth's Shape

• The green line is 12,714 km

• The red line is 12,756 km

• The Earth is slightly wider than taller

• What you may not know is how this affects gravity.

The Shape of Earth and Gravity

• Gravity pulls everything down towards the Earth

• Gravity is really pulling us towards the center of the Earth

• This means the further you are from the center of the Earth the weaker gravity is.

• So how does the shape of the Earth affect gravity?

How the shape of the Earth affects gravity

• Gravity depends on distance from the center of the Earth

• The end points of the green line are closer to the center of the Earth than the end points of the red line

• This means that at the North and South Pole the gravity is stronger than at the equator (the red line)

• This means you weigh more at the poles than at the equator

Multiple Choice

Gravity is weakest at the

• North Pole

• South Pole

• Equator

Multiple Choice

Gravity is pulling you towards the

• ground

• the center of the Earth

• the moon

• destiny you deserve