PEOPLING × TECHNOLOGY

A Year Fixed by a Solar Storm

1021 CE

History · Middle Ages · Holocene · Meghalayan

At L'Anse aux Meadows, on the northern tip of Newfoundland, Norse hands felled trees with metal blades in the year 1021 CE. The date is exact because a solar particle storm in 993 left a radiocarbon spike in the rings of every tree then alive, a marker from which the remaining rings need only be counted. This is the first firmly dated European presence in the Americas, and the earliest known moment at which human migrations, east and west out of Africa, had encircled the globe.

Why it matters

Half a millennium before Columbus, the Atlantic had been crossed and the crossing abandoned; contact is not destiny. The date is the other marvel: a flare on the Sun a thousand years ago now serves as a cosmic timestamp, sharp to the year, in scraps of wood the Norse had cut. Physics handed archaeology a calendar accurate to the single year, and here it settled a date that decades of radiocarbon had left blurred.

Dating & uncertainty

A cosmic-ray burst in 993 CE spiked radiocarbon in every tree alive that year; counting the rings from that marker out to the bark of wood the Norse cut gives 1021 CE exactly. The settlement's span is looser: the older radiocarbon dates spread over a few decades around 1000, and a Bayesian reanalysis suggests Norse activity may have endured for a century.

Sources

1. Kuitems et al. (2022), Nature · Evidence for European presence in the Americas in AD 1021doi:10.1038/s41586-021-03972-8
2. Ledger et al. (2019), PNAS · New horizons at L'Anse aux Meadowsdoi:10.1073/pnas.1907986116
3. Nydal (1989), Radiocarbon · A critical review of radiocarbon dating of a Norse settlement at L'Anse aux Meadows, Newfoundland Canadadoi:10.1017/s0033822200012613

Our species’ history as one day

23:55:244 min 36 s before midnight

if the 315,000 years of Homo sapiens were compressed into a single day