♀️ Venus: The Solar System's Hottest Planet

Venus is the second planet from the Sun and the hottest in the solar system, with a surface temperature around 465°C (870°F) -- hot enough to melt lead -- caused by a runaway greenhouse effect in its thick carbon dioxide atmosphere.

A Runaway Greenhouse World

Venus's atmosphere is over 90 times denser than Earth's and made almost entirely of carbon dioxide, with clouds of sulfuric acid. This traps solar heat so effectively that Venus stays hotter than Mercury even though it orbits farther from the Sun. Surface atmospheric pressure is roughly equivalent to being nearly a kilometer underwater on Earth.

Backwards and Slow

Venus rotates in the opposite direction to most planets (retrograde rotation) and extremely slowly -- one rotation takes 243 Earth days, longer than its own year of 225 Earth days. This means a day on Venus (sunrise to sunrise) is shorter than its year, and the Sun would appear to rise in the west and set in the east.

Earth's Near-Twin in Size

Venus is very close to Earth in size and mass, sometimes called Earth's 'sister planet' -- but its evolution diverged dramatically, likely due to its proximity to the Sun triggering a runaway greenhouse effect early in its history that boiled away any surface water.

Exploration

The Soviet Union's Venera program achieved the first successful landing on another planet with Venera 7 in 1970, and Venera 13 returned the first color images of Venus's surface in 1982 before succumbing to the extreme heat and pressure within about two hours. NASA's Magellan mission (1990-94) mapped Venus's surface using radar, which can penetrate the thick cloud cover.

Frequently Asked Questions

Why is Venus called Earth's twin?

Venus is close to Earth in size, mass, and composition, and was likely more Earth-like billions of years ago -- but a runaway greenhouse effect transformed it into the hottest, most hostile planet in the solar system.

Can you see Venus from Earth without a telescope?

Yes. Venus is typically the brightest planet in the sky and often the third-brightest natural object visible from Earth after the Sun and Moon, frequently called the 'morning star' or 'evening star.'

Does Venus have moons?

No -- Venus and Mercury are the only two planets in the solar system without any moons.