Venus

About

Venus is the second planet from the Sun and Earth's closest planetary neighbor. Often called Earth's "twin" due to its similar size and mass, Venus is a world of extremes with surface conditions that are utterly inhospitable. Its thick atmosphere, composed of 96.5% carbon dioxide, creates a runaway greenhouse effect that makes it the hottest planet in the solar system.

The surface pressure on Venus is about 92 times that of Earth — equivalent to being nearly a kilometer underwater in Earth's oceans. Clouds of sulfuric acid blanket the planet, completely obscuring the surface from view and reflecting about 70% of sunlight, which makes Venus the brightest natural object in Earth's night sky after the Moon.

Venus rotates backward compared to most planets (retrograde rotation), and it does so extremely slowly. A Venusian day is longer than its year: it takes 243 Earth days to complete one rotation but only 225 Earth days to orbit the Sun. Radar mapping by spacecraft has revealed a surface dominated by volcanic plains, with large shield volcanoes and vast lava flows.

Key Facts

• Venus is the hottest planet in the solar system at ~465°C, hot enough to melt lead, despite being farther from the Sun than Mercury.
• It rotates in the opposite direction to most planets — on Venus, the Sun rises in the west and sets in the east.
• Venus has no moons and no rings, much like Mercury.
• The atmospheric pressure at the surface is 92 times that of Earth.
• Venus has more volcanoes than any other planet in the solar system, with over 1,600 major volcanoes identified.
• The planet's upper atmosphere experiences winds up to 360 km/h, circling the planet in just four Earth days (super-rotation).
• Venus was the first planet to be visited by a spacecraft (Mariner 2, 1962) and the first to have a successful surface landing (Venera 7, 1970).

Exploration History