- Other bodies
- Basic Definitions
The astronomical symbol for Venus is a cross surmounted by a circle depicting femininity. Astronomers refer to Venus as Earth's sisterplanet since both planets show similarity in their size, density and volume. However, with astronomical observations, scientists have proved that Venus is very different from Earth. Unlike Earth, Venus has no oceans and is surrounded by an atmosphere composed mainly of carbon dioxide with no water vapor. The surface atmospheric pressure ofVenus is 92 times that of the Earth's at sea-level.
Globe Venus Inset Venus
Composition & Structure
Atmospheric composition (by volume) :
- 96.5 percent carbon dioxide
- 3.5 percent nitrogen, with minor amounts of sulfur dioxide, argon, water, carbon monoxide, helium and neon
Venus magnetic field is 0.000015 times that of Earth's field
- Venus' metallic iron core is roughly 2,400 miles (6,000 kilometers) wide
- Venus' molten rocky mantle is roughly 1,200 miles (3,000 kilometers) thick
- Venus' crust is mostly basalt, and is estimated to be six to 12 miles (10 to 20 kilometers) thick on average
Venus is the hottest in the system. Though Venus isn't the planet nearest to the sun, its dense atmosphere traps heat during a runaway version of the atmospheric phenomenon that warms up the world. As a result, temperatures on Venus reach 870 degrees F (465 degrees C), hot enough to soften lead. Scientists have probe that they have landed there and have survived solely a number of hours before getting destroyed.
Venus features a hellish atmosphere as well, consisting chiefly of greenhouse gas with clouds of oil of vitriol, and scientists have solely detected trace amounts of water in the atmosphere. The atmosphere is heavier than that of the other planet, resulting in a surface pressure ninety times that of Earth.
It takes atleast 243 Earth days for Venus to rotate on its axis, far and away the slowest of any of the major planets, and because of this sluggish spin, its metal core cannot produce a magnetic field just like the Earth's.
One of the distinguishing features of Venus is that it rotates from east to west, instead of west to east as a majority of the other planets do.
So far, four successful missions have been launched to Venus namely the Pioneer Venus mission by NASA (1978), Venera 15 & Venera 16 missions by the Soviet Union (1983-1984), and Magellan radar mapping mission by NASA (1990-1994).
Venus has a mean surface temperature of about 500 degrees C making it hotter than Mercury. This high temperature is a result of the greenhouse effect caused by the heavy atmosphere of carbon dioxide wherein sunlight enters the atmosphere to heat the surface but is trapped inside by the heavy atmosphere of carbon dioxide.
Surfaces Of Venus
The surface of Venus comprises of vast plains covered by thick lava flows and mountains or bright highlands. Maxwell Montes in Ishtar Terra is the highest peak on Venus. The surface does not house any liquid water and therefore it cannot account for the bright highlands on the surface. However, a theory says that the presence of metals can be accounted for the brightness. Venus has a very dense atmosphere comprising mainly of carbon dioxide and nitrogen. The rotation speed of Venus is about 6.5 km/h which is very slow as compared to Earth’s rotation speed at 1670 km/h.
Owing to the dense atmosphere, the surface temperature of Venus reaches up till 5000C making it the hottest planet in the solar system. On the contrary, the greenhouse effect is also responsible in keeping the planet much cooler.
The surface of Venus has been subject to lesser meteor attacks as compared to Mercury or Mars. The dense atmosphere breaks up the large meteors and burns the smaller meteorites.
Transit of Venus
A transit of a planet occurs when it passes directly between the Sun and Earth. During a Venus transit, Venus can be seen from the Earth as a small black dot or disc moving across the Sun. Venus appears much smaller on the Sun’s surface as it is much further away from the Earth.
A transit of Venus is rare and occurs every 243 years in pairs of transits 8 years apart. The most recent transit by Venus was observed on June 8, 2004 and the next transit will be on June 6, 2012.
In 1631, Johannes Kepler became the first person to predict the occurrence of a transit of Venus. However, its first observation was made only in 1639 by Jeremiah Horrocks.