Precession Precession is caused by the gravitational effects of the sun and moon.
{"Image DocumentName": "Precession The pole will be closest to Polaris ~ A.D", "Image ImageDescription": "As a result of precession, the celestial north pole follows a circular pattern on the sky, once every 26,000 years. Precession is caused by the gravitational effects of the sun and moon. The pole will be closest to Polaris ~ A.D There is nothing peculiar about Polaris at all (neither particularly bright nor nearby etc.) ~ 12,000 years from now, the celestial north pole will be close to Vega in the constellation Lyra. Earth\u2019s axis currently points nearly toward the star Polaris. About 12,000 years from now\u2014almost halfway through one cycle of precession\u2014Earth\u2019s axis will point toward a star called Vega, which will then be the North Star. Five thousand years ago, the North Star was a star named Thuban in the constellation Draco. The circle shows the precessional path of the north celestial pole among some prominent northern stars. Tick marks indicate intervals of a thousand years.", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}