The region of the uppermost atmosphere where temperature increases along with the altitude due to the absorption of solar ultraviolet radiation by ozone. The stratosphere extends from the tropopause (10–15 kilometers) to approximately 50 kilometers, where it is succeeded by the mesosphere.
The highest point in the sky reached by a celestial body.
The point in the sky vertically above a given position or observer; the point in the celestial sphere opposite the nadir.
Highest point or state; peak.