The Southern Hemisphere is that part of a rotating astronomical body that lies south of the equator. The word hemisphere (from the Greek word σφαιρα (sphere) +ημι (half)) literally means 'half ball' or "half sphere". It is also that half of the celestial sphere south of the celestial equator.
On Earth the Southern Hemisphere contains all or parts of four continents (Antarctica, Australia, about 9/10 of South America and the southern third of Africa), three oceans (South Atlantic, Indian, and South Pacific) and most of Oceania. Several islands off the Asian continental mainland are also in the Southern Hemisphere. Due to the tilt of Earth's rotation relative to the Sun and the ecliptic plane, summer is from December to March and winter is from June to September. September 22 or 23 is the vernal equinox and March 20 or 21 is the autumnal equinox.
Patagonia is a region located at the southern end of South America, shared by Argentina and Chile. The region comprises the southern section of the Andes mountains to the southwest towards the Pacific ocean and from the east of the mountain range to the valleys it follows the Colorado River south towards Carmen de Patagones in the Atlantic Ocean. To the west, it includes the territory of Valdivia through Tierra del Fuego archipelago.
The name Patagonia comes from the word patagón used by Magellan in 1520 to describe the native people that his expedition thought to be giants. It is now believed the Patagons were actually Tehuelches, who tended to be somewhat taller than Europeans of the time.