Somewhere on Earth there should be a little sign that says “Earth – Twinned with Venus”. The fact is that, due to the similarity in size and composition, Venus and Earth are sometimes referred to as “twins”. Venus is also the closest planet to Earth making it our near neighbor. So what facts are there about Venus?
Venus is the brightest object in Earth’s sky at night, aside from the moon. So bright in fact that Venus can sometimes be seen during the day when it is at its brightest, just before sunrise or sunset. Venus is often called the morning or evening star because of this visibility in our skies. The planet can be seen on the western horizon
Size and composition
Venus’ diameter is about 7,520 miles (12, 100 meters) and approximately 400 miles (644 meters) smaller than Earth. This makes Venus the 6th largest planet in our solar system.
Venus is known as a terrestrial planet and is like the Earth in that it has a crust, mantle and core. It is a rocky planet and is thought to have an iron core. The rocky layer covering the core also contains lava.
The surface of Venus is an extremely unpleasant place. It is hot and dry. Scientists have had difficulty seeing Venus’ surface. This is due to Venus being wrapped in dense layers of sulfuric clouds. Like Earth there are mountains, valleys and level ground on Venus but there is absolutely no sign of surface water due to the high temperatures.
Venus has thousands of volcanoes, 6 mountain regions and some impact craters caused by asteroid collisions. A unique feature of Venus is the presence of ring structures known as corona. Scientists believe this formed from hot material such as lava rising to the planet’s surface.
Venus atmosphere is up to 95% carbon dioxide with traces of nitrogen and water vapor. It is the heaviest atmosphere of any planet.
Venus’ surface temperature is also higher than the other planets, around 870F (465C). Its cloud layer is cooler at around 55F (13C). It is certainly too hot for any Earth life to survive there. No-one is yet sure if life exists or existed on Venus but it would not be life we are familiar with due to the heat.
Venus has slightly less density and mass than Earth. Comparing a piece of Venus to an identical piece of rock would result in only a small difference. The atmospheric pressure of Venus is 92 times that of Earth.
Rotation
Only Mercury is closer to the Sun. Venus’ average distance (average because Venus’ orbit makes a difference as it follows its course) from the Sun is 67.2 million miles (108.9 million km) compared to 93 million for Earth.
Like Earth, Venus rotates on an axis but it is not vertical. Venus axis tilts at roughly 3 compared to Earth’s 23.5. Unlike Earth, Venus rotates in what is known as a retrograde action. Simply put it means that Venus rotates in the opposite direction to the Sun. One day on Venus is equal to 243 Earth days.
Exploration
Between 1962 and 1974 both American and Russian crafts “buzzed” Venus but did not land (although Venera 9 crashed on the surface). On October 25th 1975 Venera 10 landed on Venus and managed to transmit information about rock composition, atmosphere and photographs of the surface.
In December of 1978 American and Russian craft went into orbit around Venus and transmitted enough information to make maps, give temperature readings, chemical information and readings from the lower atmosphere.
The Magellan probe was sent to Venus in August of 1990. It was intended to map the surface of Venus and eventually managed to send by images of 98% of it along with various precision measurements.
The latest mission is the Venus Express which is the first orbiting craft sent up by the European Space Agency. It was launched 9th November 2005 and took 150 days to get into orbit. Its mission was similar to the others in that it collects data on Venus but it was also being used to look at Earth from Venus’ orbit.
NASA page on Venus
