Venus

Venus Facts

How much do you know about the planet Venus? Let’s learn some more facts!

Venus is the planet most like Earth – in some ways. It’s almost exactly the same size and it has a similar structure too, with a hard crust over a soft mantle and probably a molten core.

Venus facts

Venus is much further from the sun than Mercury, so you’d think it would be cooler, but in fact it’s much hotter – and it doesn’t cool down at night.

Venus has many huge volcanoes, and the weather is extreme and bizarre. It’s definitely not a place you’d want to visit!

Venus Overview

Mass:  10,708,104,000,000,000 billion lb (4,867,320,000,000,000 billion kg)

Orbit Size (semi-major axis): 67,238,251 miles (108,209,475 km)

Mean Radius: 3,760.4 miles (6,051.8 km)

Volume: 222,738,686,740 cubic miles (928,415,345,893 km3)

Density: 3.030 oz/cu in (5.243 g/cm3) – 0.951 times the density of Earth

Venus Facts

Venus is the closest planet in size to Earth – the difference in diameter is only 403 miles (650 km). It’s often described as Earth’s sister planet.

venus earth size comparison

A year on Venus (the time it takes for it to go round the sun once) is 225 Earth days.

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A day on Venus (the time it takes to rotate once) is 243 Earth days so there’s less than one day in a year!

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Or is there? All the planets orbit the sun in an anti-clockwise direction. Most of them also rotate anti-clockwise – except Venus. It rotates clockwise, so if you were on Venus the sun would appear to rise every 117 Earth days. Unlike on Earth, it would rise in the west and set in the east.

Does Venus Have Moons or Rings?

Venus is one of only two planets that doesn’t have any moons or rings. The other is Mercury. This is probably because they’re the closest planets to the sun.

If a moon was too close to the planet it would be ripped apart by tidal effects; if it was far enough away to avoid that the sun’s huge gravity would pull it away from the planet.

the sun gravitational force

Venus is named after the Roman goddess of love and beauty, because it’s one of the brightest objects in the night sky.

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The orbital speed of Venus is 21.76 miles (35.02 km) per second. That’s slightly faster than Earth, which is travelling at 18.5 miles (29.78 km) per second.

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Gravity is 0.904 of Earth’s. If you weigh 100 pounds on Earth you’d weigh 90.4 pounds on Venus.

What is the Atmosphere on Venus Like?

The atmosphere on Venus is very, very thick. That means the pressure at the surface is very high – 90 times higher than on Earth. In fact it’s the same pressure you’d feel a mile and a half under water. That’s enough to crush almost all submarines.

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Even if the atmosphere wouldn’t flatten you, you couldn’t breathe it. It’s mostly carbon dioxide. That’s why Venus is so hot; it has an extremely strong greenhouse effect that traps heat in the atmosphere.

greenhouse effect venus

The greenhouse effect means temperatures are similar all over the planet. It doesn’t cool down at night and, unlike Earth, the poles are as hot as the equator. The only places that are slightly cooler are high mountains.

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The atmosphere also contains clouds of sulphuric acid. This falls as rain, but because the surface is so hot it evaporates back into a gas when it’s still 16 miles (25 km) above the ground.

Venus and Earth

Venus has an ozone layer, like Earth.

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Scientists think Venus used to be a lot more like Earth than it is now, but evaporated water caused a greenhouse effect that got out of control. Finally the planet got hot enough to boil off all the water, which escaped into space.

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Although the clouds on Venus are sulphuric acid, not water, they cause lightning just like clouds on Earth do.

lightning in space

There are few craters on Venus because the atmosphere is so thick; most asteroids that fall into the planet burn up before they reach the surface. Only really big ones make it through, so all the craters that do exist are large – more than a mile wide.

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Venus has almost no magnetic field. That’s probably because it rotates so slowly. Earth spins fast enough that its iron core creates a dynamo effect, producing a magnetic field that protects us against cosmic rays and the solar wind. Because Venus doesn’t have one the solar wind blows away the lighter gases in the atmosphere.

no magnetic field on venus

The ancient Greeks thought Venus was two different objects – the morning star and evening star. That’s because without a telescope it looks like a very bright star, and it’s visible just after sunset and just after dusk.

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The Mayans and Babylonians weren’t fooled – they knew it was the same object.

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Galileo Galilei was the first person to look at Venus through a telescope. He saw that it has phases like the moon – sometimes it’s a full disk, sometimes a crescent. Galileo realised that meant it orbited the sun, not Earth.

Space Missions to Venus

The Soviet Union was the first country to try to send a spaceship to Venus, but their first three missions failed. The first US mission also failed but NASA’s Mariner 2 flew past Venus in December 1962 and sent back microwave images.

Mariner 2 venus

In 1970 the USSR launched Venera-7, which landed on Venus on December 15. It transmitted data from the surface for 23 minutes, then failed. Its electronics probably melted; the temperature was 887°F (475°C).

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After Venera-7 the Soviets landed another nine probes on Venus and collected a lot more data. NASA and European orbiters have collected even more. Future missions might include robot aircraft that can survive in the planet’s atmosphere.

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