Venus

Venus is the second planet from the Sun. It is almost the same size as Earth, but it has no liquid water.

Venus has a thick atmosphere made of carbon dioxide. This atmosphere has clouds of sulfuric acid. The surface of Venus is very hot, about 464 °C (867 °F). The pressure there is 92 times greater than on Earth.

From Earth, Venus looks like a bright star. People sometimes call it the "morning star" or "evening star" because it shines very brightly at night. Venus is closer to the Sun than Earth is. It sometimes comes closer to Earth than any other planet. This makes Venus a useful stop for spacecraft traveling around the solar system.

Venus turns very slowly, but in the opposite direction of most planets. It takes about 117 Earth days to turn once. A year on Venus, the time it takes to go around the Sun, is about 225 Earth days. Venus does not have any moons. It also has a weak magnetic field. Inside Venus, there is a core, mantle, and crust. Venus has active volcanism instead of the moving plate tectonics found on Earth.

In the past, Venus might have had liquid water. Today, scientists are interested in Venus because some parts of its clouds might be like Earth. They wonder if there could be life on Venus. Many spacecraft have flown by Venus since 1961. More missions to Venus are planned for the future.

Physical characteristics

Venus is one of the rocky planets in our Solar System. It is similar in size and mass to Earth. Venus spins very slowly, so it is almost round. It has a very thick atmosphere made mostly of carbon dioxide. This creates a strong greenhouse effect, making the surface of Venus extremely hot.

The surface of Venus was a mystery until probes visited in the 20th century. These probes showed a landscape covered in sediment and rocks. Scientists have mapped Venus and found volcanoes, mountains, and many unique features. Most of the surface is smooth volcanic plains, with two large highland areas. Venus also has special volcanic shapes not found on Earth, like pancake-like features called "farra" and spiderweb-like cracks called "arachnoids."

Atmosphere and climate

Main article: Atmosphere of Venus

Further information: Extraterrestrial sky § Venus

Venus has a very thick atmosphere made mostly of carbon dioxide. It also has some nitrogen and a few other gases. This atmosphere is about 92 times heavier than Earth’s. It creates very high pressure on the surface, like being deep underwater on Earth.

Because of the thick atmosphere and lots of carbon dioxide, Venus has a strong greenhouse effect. This makes Venus extremely hot, even hotter than Mercury, which is closer to the Sun.

The clouds on Venus are made of sulphuric acid. They cover the whole planet and reflect a lot of sunlight. This makes Venus very bright from space. The atmosphere moves very fast, with winds that go around the planet much quicker than Venus itself rotates. Scientists study Venus to help understand how Earth’s climate might change in the future.

Orbit and rotation

Main article: Orbit of Venus

Venus goes around the Sun at about 108 million kilometers away. It finishes one trip around the Sun in 224.7 days. Its path is almost a perfect circle, much better than most planets.

Most planets spin one way, but Venus spins the opposite way. If you looked down at its north pole, it would spin clockwise. This makes a day on Venus last longer than a year on Venus — 243 Earth days! Because of this, if we could see the Sun through Venus's thick clouds, it would look like the Sun rises in the west and sets in the east. Venus does not have any moons.

Observability

Venus is very easy to see in the night sky. With your eyes alone, it looks like a bright white star, even brighter than any real star. It is the brightest thing in the sky after the Sun and the Moon. Venus can sometimes be seen during the day if you know where to look, though this is rare.

Venus moves in its position compared to Earth and the Sun every 584 days. This makes it appear either after sunset, called the “Evening Star,” or before sunrise, called the “Morning Star.” Because it is so bright, Venus is often mistaken for an unidentified flying object.

Phases

Main article: Phases of Venus

When you look at Venus through a telescope, it shows phases like the Moon. When it is far from the Sun, it looks like a thin crescent. When it is closer to Earth, it looks like a full disc. You can see these phases with even a small telescope.

Daylight apparitions

Venus can sometimes be seen in the daytime if the sky is clear and you know where to look. Famous people such as emperor Napoleon Bonaparte and president Abraham Lincoln said they saw it during the day.

Transits

Main article: Transit of Venus

A transit happens when Venus moves directly between Earth and the Sun, looking like a small black dot moving across the Sun. These transits are rare, happening in pairs more than a century apart. The last transit was in 2012, and the next one will be in 2117.

Ashen light

Some people have seen a faint glow on the dark side of Venus when it is a thin crescent. This glow, called “ashen light,” might not be real and could just be an optical illusion.

Observation and exploration history

Main article: Observations and explorations of Venus

Venus is bright enough to see without any special equipment, so people have known about it for a very long time. Ancient people saw Venus as the "morning star" when it appeared before sunrise and the "evening star" when it appeared after sunset. They didn’t realize it was the same object until later.

In the 1600s, Galileo used a telescope and discovered that Venus changes shape, like the Moon. This showed that Venus orbits the Sun, not the Earth. In the 1700s, scientists discovered Venus has an atmosphere. In the 1960s, space probes began visiting Venus. These probes learned a lot about Venus, including that its surface is very hot and that it has a thick atmosphere. Today, scientists are planning more missions to Venus to learn even more about this fascinating planet.

Possibility of life

Main article: Life on Venus

Some scientists think tiny life might exist high in the clouds of Venus, about 50 kilometers above the surface. In these clouds, the temperature and pressure are more like Earth’s. The clouds have water, carbon dioxide, and sunlight — things needed for life.

In the past, some scientists thought they saw signs of tiny organisms in Venus’s clouds. They looked for a gas called phosphine, which might be a sign of life. But later studies found other reasons for this gas. Because Venus’s surface is too hot for life, the idea of life is only about these upper cloud layers. More research is needed to learn more.

In culture

Venus is one of the brightest objects in the night sky. Many cultures have given it special meaning in myths, stories, and art. In ancient times, people in places like Mesopotamia and Egypt saw Venus as a goddess. The planet’s appearance in the sky, sometimes as the "morning star" and sometimes as the "evening star," inspired many stories and poems.

Later, in cultures such as Greece and Rome, Venus was linked to the ideas of love and beauty. Today, Venus still appears in books, music, and even flags—like the flag of Chile, which shows a bright star that is actually Venus.