Museo Galileo
italiano
Virtual Museum
In-depth
Hemisphere
Hemisphere

One-half of the Earth's surface obtained by dividing the Earth by means of a plane passing through its center. Typically, the plane is at right angles to the Earth's axis and divides the planet into a northern (or Arctic or boreal) hemisphere and a southern (or Antarctic or austral) hemisphere. The first comprises the Earth's surface above the equator; the second comprises the Earth's surface below the equator.