Venus is known as the Earth's "twin" because the two planets are so similar in size.
The diameter of Venus is about 7,520 miles (12,100 kilometers), approximately 400 miles (644 kilometers) smaller than that of the Earth.
At its closest approach, it is about 23.7 million miles (38.2 million kilometers) away.
As seen from the Earth, Venus is brighter than any other planet or even any star.
Although Venus is called the Earth's "twin," its surface conditions appear to be very different from those of the Earth.
Geologists have had difficulty learning about the surface of Venus because the planet is always surrounded by thick clouds of sulfuric acid.
Venus has a variety of surface features, including level ground, mountains, canyons, and valleys. About 65 percent of the surface is covered by flat, smooth plains.
On these plains are thousands of volcanoes, ranging from about 0.5 to 150 miles (0.8 to 240 kilometers) in diameter.
Six mountainous regions make up about 35 percent of the surface of Venus.
One mountain range, called Maxwell, is about 7 miles (11.3 kilometers) high and about 540 miles (870 kilometers) long.
There are also impact craters on the surface of Venus. Impact craters form when a planet and asteroid collide.
The temperature of the uppermost layer of Venus's clouds averages about 55 degrees F (13 degrees C). However, the temperature of the planet's surface is about
870 degrees F (465 degrees C), higher than that of any
The mass of Venus is about four-fifths that of the Earth. The force of gravity on Venus is slightly less than on the Earth.
For this reason, an object weighing 100 pounds on the Earth would weigh about 88 pounds on Venus.