Venus

Introduction

Venus is the second planet from the Sun and our closest planetary neighbor. Similar in structure and size to Earth, Venus spins slowly in the opposite direction from most planets. Its dense atmosphere traps heat in a runaway greenhouse effect, making it the hottest planet in the solar system with surface temperatures hot enough to melt lead! Glimpses below the clouds reveal volcanoes and deformed mountains. Venus was named after the ancient Roman goddess of love and beauty, who was known as Aphrodite to the Ancient Greeks.

Size and Distance

With a radius of 3,760 miles (or 6,052 kilometers), Venus is about the same size as Earth — just slightly smaller.

From an average distance of 67 million miles (or 108 million kilometers), Venus is 0.7 astronomical units (AU) away from the Sun. It takes sunlight 6 minutes to travel from the Sun to Venus.

3D Model:

Orbit and Rotation

Venus' rotation and orbit are unusual in several ways. Venus is one of just two planets that rotate from east to west. Only Venus and Uranus have this "backwards" rotation. It completes one rotation in 243 Earth days -- the longest day of any planet in our solar system, even longer than a whole year on Venus! But the Sun doesn't rise and set each "day" on Venus like it does on other planets. On Venus, one day-night cycle takes 117 Earth days because Venus rotates in the direction opposite of its orbital revolution around the Sun.

Venus makes a complete orbit around the Sun (a year in Venusian time) in 225 Earth days or slightly less than two Venusian day-night cycles. Its orbit around the Sun is the most circular of any planet — nearly a perfect circle. Other planet's orbits are more elliptical, or oval-shaped.

With an axial tilt of just 3 degrees, Venus spins nearly upright, and so does not experience noticeable seasons.

Structure

Venus is in many ways similar to Earth in its structure. It has an iron core that is about 2,000 miles (or 3,200 kilometers) in radius. Above that is a mantle made up of hot rock slowly churning due to the planet's interior heat. The surface is a thin crust of rock that bulges and moves as Venus' mantle shifts and creates volcanoes.

Formation

When the solar system settled into its current layout about 4.5 billion years ago, Venus formed when gravity pulled swirling gas and dust together to form the second planet from the Sun. Like its fellow terrestrial planets, Venus has a central core, a rocky mantle and a solid crust.