The Southern Cross Was Once Visible from Britain

The Southern Cross (Crux) is now seen only from the Southern Hemisphere and low northern latitudes, but it was once visible much farther north. Its stars were entirely visible as far north as Britain in the fourth millennium BC, roughly 5,000 to 6,000 years ago. The cause is precession, the slow wobble of Earth’s axis, which changes which stars rise at a given latitude. Ptolemy treated the stars as part of Centaurus. By 400 AD the stars of Crux never rose above the horizon throughout most of Europe.