# How is the tilt of the earth determined mathematically?

##### 1 Answer

Dec 25, 2015

The obliquity, or axial tilt angle, is can be calculated by a power series based on observation.

#### Explanation:

There is a mathematical formula which can be used to determine the Earth's obliquity. It is

Where the angles are in arc seconds

Hence the obliquity is decreasing at a rate of about 46.814 arc seconds every 36525 days.