Solar minimum

Sky watchers may see more auroras, and space agencies must monitor radiation storms for astronaut protection.

[4] In hindsight the prediction proved to be wildly inaccurate and not representative of the observed sunspot numbers.

[5] During 2008–09 NASA scientists noted that the Sun is undergoing a "deep solar minimum," stating: "There were no sunspots observed on 266 of [2008's] 366 days (73%).

Prompted by these numbers, some observers suggested that the solar cycle had hit bottom in 2008.

The grand minima form a special mode of the solar dynamo operation.