The first galaxy ever written down

In his Book of the Fixed Stars, finished around 964 CE, the Persian astronomer al-Sufi described a faint patch near the constellation Andromeda as a 'little cloud.' It is the first known written record of the Andromeda Galaxy — a whole other galaxy, some 2.5 million light-years away — noted with the naked eye nearly a thousand years before telescopes revealed what it was.

One of many fact-checked wonders across eight traditions at The Spring of Wisdom.