Labels:text | screenshot | font | number OCR: FACT FILE THE POINT on the celestial sphere at which the Earth's spin axis points changes over time. Over a lifetime, this shift amounts only to about the apparent width of the Moon. Over centuries, however, this motion is dramatic. For example, if cities in the northern hemisphere, such as Vancouver or London, had existed in 3000 BC, their inhabitants would have been able to see the Southern Cross.
