Universe Today
Size, Mass, and Orbit:
Composition and Surface Features:
Atmosphere and Climate:
The surface of Venus is effectively isothermal, which means that their is virtually no variation in Venus' surface temperature between day and night, or the equator and the poles. The planet's minute axial tilt - less than 3° compared to Earth's 23° - also minimizes seasonal temperature variation. The only appreciable variation in temperature occurs with altitude.
The highest point on Venus, Maxwell Montes, is therefore the coolest point on the planet, with a temperature of about 655 K (380 °C) and an atmospheric pressure of about 4.5 MPa (45 bar).
Historical Observations:
Modern Observations:
The atmosphere of Venus was discovered in 1761 by Russian polymath Mikhail Lomonosov, and then observed in 1790 by German astronomer Johann Schröter. Schröter found when the planet was a thin crescent, the cusps extended through more than 180°. He correctly surmised this was due to the scattering of sunlight in a dense atmosphere.