Astronomy : About Venus

Venus is one of our cosmic neighbours. It can easily be seen in the sky as it is the third brightest object in the sky (-3.4 magnitude) after the Sun and the Moon. It is popularly known as the Evening Star. The fact that it is visible late in the afternoon and evening is caused by its location in the solar system - Venus is an inner planet, so it never reaches more than 48° from the Sun in the sky. For the same reason we can see phases of it, like the phases of the Moon.

The planet of the Greek love goddess is situated 107.4 to 109 million kilometers from the Sun. Out of this small difference between perihelium and afhelium it is obvious that the elliptic orbit of Venus has a small deviation (0,007 exactly). The length of the circuit around the Sun is 224,7 earth days or 0,924 days on Venus (the length of the local day is 243,01 earth days). Further, it is interesting that Venus as one of a few planets swivels in a retrograde way, in the opposite direction to that of the Earth.

Even though it appears that Venus is similar to the Earth in some ways, for example it has a similar size - the equatorial diameter is 12 102 km, the weight is 82% of the Earth's weight - earth life could probably not exist on this planet. The surface temperature is 738 K and the atmospheric pressure is 94 times greater than on the Earth which is, besides, caused by an extremely thick atmosphere. The gaseous envelope surrounding Venus consists of carbon dioxide (98%), drops of sulphuric acid and loose sulphur.

Venus' surface is the least known of all terrestrial bodies (solid bodies resembling the Earth). The sounds Vinira started mapping the terrain. The first sound sent - Vinira 1 - started in 1961. However, the first photographs of the surface were not brought until 1975, by Vinira 9.

Venus is very volcanically active. Its surface cannot be seen in ordinary light, only made possible with the assistance of radiolocation. The main part of the surface is filled with flat extensive plains but there are large depressions, as well (Atlanta Planitia) and two mountainous areas (Ishar Terra and Aphrodite Terra).

Craters caused by smaller meteorites do not occur on the surface of Venus, because such bodies burn up completely before they reach the surface. So, there are only craters created by large bodies which survive the journey through the thick atmosphere.

Here are information about Venus in numbers: