Venus

Venus

Days on Venus seem endless. Venus is the second planet from the Sun. One day on Venus is as long as 243 days on Earth. A year on Venus is only 225 Earth days long. So a day on Venus is longer than a year!

WHY DOES VENUS HAVE LONG DAYS?

Venus orbits, or goes around, the Sun just as all the planets do. It takes Venus 225 days to go around the Sun. Earth goes around the Sun in 365 days. We call the time it takes Earth to go around the Sun a year.

Venus also spins around on its axis. An axis is an imaginary line going through a planet from top to bottom. Every planet spins on its axis. One day on Earth is the time it takes for Earth to turn completely around on its axis. Earth turns once every 24 hours. Venus turns much more slowly. It takes Venus 243 Earth days just to turn once.

Venus also spins backwards around its axis. It spins in the opposite direction that Earth spins. On Venus, the Sun rises in the west and sets in the east.

WHAT IS VENUS LIKE?

Venus is more like Earth in some ways than any other planet. It is almost the same size as Earth. It is a similar distance from the Sun compared to the other planets. It is made mostly of rock and has an atmosphere (gases that surround a planet).

Venus has flat plains and high places, just like Earth. It has huge extinct (dead) volcanoes and big craters. Meteorites crashing into the planet made the big craters. But Venus has no moon.

In other ways, Venus is not at all like Earth. It is not a place you would like to visit. The atmosphere is poisonous. It is made up mainly of a gas called carbon dioxide. The clouds are filled with drops of powerful acid “rain” that would eat through your clothes—and through you. The atmosphere is so thick that its weight would crush you. There is no water on Venus.

It is very hot on Venus. The temperature on the surface is about 864° Fahrenheit (462° Celsius). That’s more than four times as hot as boiling water. No plants or animals could live in a place that hot.

WHY IS VENUS SO HOT?

The thick atmosphere of Venus keeps the planet hot. The carbon dioxide in the atmosphere of Venus is called a greenhouse gas. It acts like the glass in a greenhouse. Greenhouse glass traps heat from the Sun. The heat keeps a greenhouse warm all year long.

Earth has just enough carbon dioxide in its atmosphere to keep our planet warm enough for life. Venus has too much carbon dioxide. Venus traps too much heat from the Sun. This makes Venus too hot for anything to live there.

HOW DO WE LEARN ABOUT VENUS?

People in ancient times knew about Venus. They could see Venus when they looked up at night. Venus is brighter than any object in the sky other than the Sun and the Moon. Sometimes Venus is the first object to appear in the sky as it gets dark. Sometimes Venus is the last object to fade in the morning light. The ancient Romans called Venus the morning star or the evening star. They named Venus for the ancient Roman goddess of love and beauty.

Venus was the first planet to be visited by spacecraft. A United States spacecraft named Mariner 2 flew by Venus in 1962. Many spacecraft have visited Venus since then. These spacecraft carried instruments to take measurements. Some of them carried radar to see through the thick clouds on Venus. Radar “sees” with radio waves. Some U.S. and Russian spacecraft landed on Venus.

The spacecraft that landed on Venus had to plunge through thick clouds filled with sulfuric acid. They had to survive lightning flashes and powerful winds. The weight of the planet’s atmosphere crushed the spacecraft, and the heat on Venus baked them. Some spacecraft sent back pictures and measurements before they stopped working.