Venus, the second planet from the Sun, is often called Earth's twin due to its similar size and composition. However, its environment is vastly different, with scorching temperatures and a dense, toxic atmosphere. It is the brightest natural object in the night sky after the Moon.
Type: Terrestrial planet
Diameter: ~12,104 kilometers (7,521 miles), about 95% of Earth's diameter
Mass: ~4.87 × 10²⁴ kilograms (81.5% of Earth's mass)
Gravity: ~8.87 m/s² (90% of Earth's gravity)
Distance from the Sun: ~108.2 million kilometers (67.2 million miles)
Orbital Period: ~225 Earth days
Day Length: ~243 Earth days (longer than its year)
Surface Temperature: ~462°C (864°F) on average, hottest planet in the Solar System
Moons: None
Surface:
Venus has a rocky surface with mountains, valleys, and vast volcanic plains.
It is covered by sulfuric acid clouds, making direct observation difficult.
The surface pressure is about 92 times that of Earth, equivalent to being 900 meters (3,000 feet) underwater on Earth.
Atmosphere:
Composed primarily of carbon dioxide (96.5%) and nitrogen (3.5%).
Contains clouds of sulfuric acid, which reflect sunlight and give Venus its bright appearance.
Greenhouse effect traps heat, making Venus the hottest planet.
Geological Features:
Maxwell Montes: The highest mountain, over 11 kilometers (7 miles) high.
Ishtar Terra and Aphrodite Terra: Large highland regions.
Volcanoes: Venus has more volcanoes than any other planet, with many potentially active.
Coronae: Circular features formed by upwelling of hot material beneath the crust.
Magnetic Field:
Venus has no significant magnetic field, likely due to its slow rotation and lack of a molten core dynamo.
Retrograde Rotation:
Venus rotates in the opposite direction to most planets, meaning the Sun rises in the west and sets in the east.
Its rotation is extremely slow, taking about 243 Earth days to complete one rotation.
Closest Approach to Earth:
Venus is the closest planet to Earth, coming within about 38 million kilometers (24 million miles).
The extreme greenhouse effect causes surface temperatures to remain constant day and night.
Winds in the upper atmosphere can reach speeds of 360 km/h (224 mph), creating a phenomenon known as super-rotation.
Past Missions:
Venera Program (Soviet Union): First spacecraft to land on another planet (Venera 7, 1970).
Magellan (1990-1994): Used radar to map 98% of Venus's surface.
Pioneer Venus: Studied the atmosphere and surface using radar and probes.
Current and Future Missions:
Akatsuki (Japan): Studying Venus's atmosphere and weather.
DAVINCI+ and VERITAS (NASA): Upcoming missions to study Venus’s atmosphere and geological history.
Named after Venus, the Roman goddess of love and beauty.
Known since ancient times as the "Morning Star" or "Evening Star" due to its brightness.
Venus is the hottest planet in the Solar System, despite being farther from the Sun than Mercury.
A day on Venus is longer than its year.
Venus reflects about 70% of the sunlight that reaches it, making it the brightest planet.
Its thick atmosphere crushes and burns spacecraft quickly, making exploration challenging.
Comparative Planetology:
Helps scientists understand the effects of the greenhouse effect and planetary evolution.
Volcanism:
Studying Venus’s volcanic activity provides insights into Earth-like planets.
Atmosphere Studies:
Venus's thick atmosphere serves as a natural laboratory for studying extreme climates.
Venus’s surface conditions are inhospitable to life as we know it, but the upper atmosphere (~50 km altitude) has temperatures and pressures similar to Earth, leading to speculation about microbial life in the clouds.