The sun’s dark spots cycle every 11 years—as well as every 88, 200, and 2,400 years
(SOURCE: SILSO DATA, ROYAL OBSERVATORY OF BELGIUM, BRUSSELS; "SOLAR ACTIVITY OVER NINE MILLENNIA: A CONSISTENT MULTI-PROXY ECONSTRUCTION," BY CHI JU WU ET AL., IN ASTRONOMY & ASTROPHYSICS ; APRIL 4, 2018; DAGUERREOTYPE IMAGE OF SUN BY LOUIS FIZEAU (1845 image); CARNEGIE INSTITUTION OF WASHINGTON (1947 image); SUNSPOT DRAWING FROM JOHN OF WORCESTER’S CHRONICLE OF ENGLAND (1128 image))
