User: droovee

Re:Historic Period?

On: Three More Solar Flares

Not entirely true. The CBC has an article today. A choice quote:

Direct observations of sunspots go back to the early 17th century, corresponding to the invention of the telescope.

To get data on sunspots from before observations were possible, Ilya Usoskin, a geophysicist who worked with colleagues at the University of Oulu in Finland and the Max Planck Institute in Germany, examined ice core samples from Greenland and Antarctica.