An interesting question hit my inbox this week. How far south can an aurora be seen? Specifically, are the “northern lights” ever visible from Timbuktu?
A 2004 New York Times article about medieval Arabic manuscripts triggered the question. The city of Timbuktu, Mali, was one of Africa’s intellectual hubs when the Renaissance was barely a twinkle in Europeans’ eyes. The article focused on efforts to rescue the ancient manuscripts.
One 16th-century scholar, Mahmoud Kati, scribbled notes on various subjects in the margins of his books. In August 1583, he wrote:
“…after half the night had passed stars flew around the sky as if fire had been kindled in the whole sky — east, west, north and south. It became a mighty flame lighting up the earth, and people were extremely disturbed about that. It continued until after dawn.”
Does this describe the annual Perseid meteor shower? The image of meteors as sparks from a fire points to this conclusion. And the meteors are best seen after midnight.
But the second line sounds a lot like an auroral display. In fact, bright aurorae seen from the latitudes of the U.S. and the Mediterranean often appear as a deep red glow. In A.D. 37, the Roman emperor Tiberius sent troops to assist the port of Ostia when the red aurora shone “like a vast and smoking fire.” On September 15, 1839, a similar display dispatched fire departments throughout London.
I’ve been fooled, too. In 1980, while tending my Vermont college observatory, I spotted a wavering orange glow to the west and fully expected to hear sirens. Instead, the fiery glow morphed into a great auroral display.
During the big solar storms of spring 1989 and fall 2003, observers as far south as Jamiaca reported seeing aurorae. Jamaica is located at 18° north latitude; Timbuktu is at 16° north. So, it’s certainly possible Kati’s note describes an aurora — or, perhaps more likely, conflates meteor and aurora observations.
In fact, there were many European aurorae reports in 1583, particularly in August. The National Geophysical Data Center (NGDC) has a digital list of middle-latitude auroral sightings for the past 900 years. The list comes to us from a paper published by the Czechoslovak Academy of Sciences in 1988, which the NGDC digitized in the 1990s as part of a “data rescue project.”
One endangered document deserves another.