(daily way in the model 3 m)
At a distance of 108 km
from the sun (0.72 astronomic units) and with a diameter of 12,104 km, Venus is
the second innermost planet in the system.
It takes Venus 225 earth days to orbit our central star in an almost circular path. It needs 243 days for one rotation around its axis and it spins in a different direction to the rest of the planets (retrograde rotation). That's why it takes 117 earth days from one sunrise to the next on Venus. Because of its slight rotation there is no magnetic field. Our inner neighbouring planet has been explored by more than 20 space probes up to now, of which the first,"Mariner2", went in 1962. At about 500°C the surface of Venus, where unmanned spacecrafts have already landed (Venera, 1975), is very hot. The atmosphere contains just little steam, but droplets of sulphuric and sulphurous acid. The inhospitably high temperatures are due to the great amount of carbon dioxide, which produces a massive greenhouse effect. Even a fraction of it would wipe out life on earth. Because of the high density of the atmosphere, on the surface of our inner neighbour there is an equally high pressure (ca. 90 bar), which is equal to the pressure 1000 metres below sea level on earth. The core of Venus is similar to that of the earth. Volcanic activity determines the shape of the planet's surface. There are some craters but all of them are big because the smaller asteroids burn up in the thick atmosphere. The outline of Venus, like the phases of the Earth's moon, changes from a thin crescent to an almost totally round disc, however, the surface of Venus is unable to be seen by man-made telescopes because it is concealed by a thick layer of cloud. There was a satellite imagined by Cassini (1625 - 1712), but up to now, all those presumed companions of Venus (named "Kleinchen" by German astronomers) have turned out to be asteroids that happened to cross Venus' orbit. Presently there is an alternating double transit movement of Venus after 105,5 and 121.5 years with an interval of exactly 8 years, which turns out to be a cycle of 243 years. During this transit Venus shows itself between the Earth and the Sun for a period of about 6 hours. On Dec. 4th 1639, the unbelievably young English astro - genius Jeremiah Horrocks was the first person to predict and observe a transit movement of Venus and he described it with impressive words.
The rare act of Venus passing in front of the sun's sphere will be repeated for our viewing on the morning of June 8th, 2004.
brightest planet after the Sun and the Moon, Venus and its time of visibility
has always been known to astronomers. Venus can appear, like Mercury, not only
as a morning star but also an evening star, depending on whether Venus
emerges just `after` or just `before` the sun in the shining heavenly sphere.
Then Venus is, in any case, visible for about 269 days (9 months). The pregnancy
period of a human lasts just as long. Because of this Venus became the goddess
of sexual love to most old cultures because she brings a shining heavenly light
to the cycle and also offers a time period. It takes 584 earth days for Venus to
appear as a morning star (Latin: Lucifer = the one who brings the light) and
then to re-appear. Almost exactly 8 years or 99 moonmonths pass in five of these
periods, which is expressed in many old calendars and myths. From the
commensurable periods of the Sun, the Moon and Venus it shows that at
about every eight years these three planets are in the same places in the sky
(584 x 5 = 365 x 8 = 2920 =ca. 29,5 x 99). The five positions at the beginning
of each one of Venus' periods create a pentagram on the zodiac, also known as
the pentacle. The Greek poet Hesiod explains the origin and name of Aphrodite in
the following way : Once Kronos / Saturn wanted to gain world supremacy. He
castrated his father Uranos / Coelos and threw his genitals into the sea.
Aphrodite originated from this foam (Greek: aphros), hence the German name
"die Schaumgeborene". Her husband was Hephaistos / Vulcanus, the
legendary blacksmith who created valuable arms and tools and an enormous mill.
The love goddess often deceived him, one time with Ares / Mars and from this the
god of sexual love Eros / Amor was created. The month of April
could have derived its name from Aphrodite but it could also have come from the
Latin word `aprire`(to open).
The day of the week that is dedicated to planet Venus is Friday, German: Freitag, Italian: venerdi. Freya, Isis, Ishtar, Earandel and Jubar are some other mythological names of the god corresponding to it.
Picture : Aphrodite by Botticelli.