# Moon Graphic: Oblate Spheroid

## Swipe to Rotate 3D View of the Moon

Earth's moon appears like a sphere as viewed from Earth.
However in reality the shape of the moon approximates
the shape of
an *oblate spheroid*, like a slightly flattened
ball.

Earth is not a sphere either. Earth may be described as an oblate spheroid with some variation. The earth's diameter is larger at the equator. Additionally mountains and oceans modify the shape of the earth. Some people say the earth is slightly tear drop shaped caused by the gravitational pull of the sun.

The minor axis is the smaller radius of an ellipse. The major axis is the larger radius of an ellipse. An ellipse rotated around it's minor axis is considered an oblate spheroid.

If an ellipse's major and minor axes are equal in diameter, then the ellipse is a circle. A sphere results from rotating a circle around either axis.

The Earth map came from NASA images. Seven Thunder Software modified the graphic for 3D display online.