How Does Precession Affect Night Sky

In astronomy, precession is an important concept that determines our view of the night sky. Over the centuries, our view of the night sky has changed due to precession. As a result, everyone should have the right and a duty to know about astronomy. Precession impacts our night sky; thus it is crucial to be aware of.

Precession is caused by the axis of rotation twisting due to the gravitational pull of the sun and the moon that makes the Earth’s axis upright relative to its orbit thus, causing the precession or wobble (Seeds 20). One cycle of precession of the Earth’s axis occurs every 26,000 years (Seeds 20). Precession of the Earth is like a spinning top because the weight at the top of the Earth and the rapid spinning of the Earth on its axis causes it to tip on either side. This leads to a cone shaped path like that of a spinning top (Seeds 17). …show more content…
Precession causes the reference marks to slowly move (Seeds 20). This then leads to a different night sky. For example, 4,800 years ago Egyptians recorded that the star Thuban (alpha Draconis) was close to the north celestial pole. Currently, Polaris is the closest star to the pole and by 2100 Polaris will be the closest it has ever been to the pole. It is projected that in 12,000 years the pole will be within 5° of the star Vega (alpha Lyrae) (Seeds 20). Over time, the night sky has