Ancient astronomers chronicled the shifting heavens, diligently charting the movements of our star-studded canopy. The moon’s face morphed nightly, our planetary neighbors came and went, and occasionally a brilliant, icy vagrant would sweep by.

But the stars? Those stayed pretty much in the same place, relative to one another. So when new, starry points of light briefly appeared and then faded away, Earth’s sky gazers noticed.

Nearly 1,000 years ago, one of these new stars began shining brightly in the northern sky. It was July 4, 1054, and the people of Earth – from North America to China – turned their attention skyward. Glimmering near the star Zeta Tauri, the new star was much more than a distant, pale point of light: