In relation to the Sun, Venus is the second planet after Mercury, just in front of the Earth. It is the only planet that shines stronger than the Sirius star, with a magnitude that can exceed -4.5 when it is close to the Earth (lower opposition).
Like Mercury but in a much brighter way because more brilliant, Venus is the first “star” that appears above the western horizon at night or the last that disappears in the morning above the eastern horizon.
Observed in a small telescope (50 mm in diameter) or even in 7×50 binoculars, we can observe the evolution of its disc that gradually changes from the shape of a small sphere to that of a large crescent moon 6 times more great.
Closer to Earth, Venus is only 41 million kilometers, which explains the large size of its crescent (60-66 “) which is 1.5 to 2 times larger than the apparent diameter of Jupiter (30-50 “) and takes on a cream-yellow color with slightly fuzzy edges due to its thick atmosphere.
Venus gravitates 108 million kilometers from the Sun. Its year lasts 224.7 days and it turns on itself in 243 days. In other words, on Venus the day lasts 117 terrestrial days. In addition, Venus is inclined 178 ° in its orbit, which means that on Venus the South Pole is to the north and the Sun rises to the West and sets to the East!
With a diameter of 12104 km, Venus is the twin sister of the Earth. Unfortunately it hides its surface under a thick atmosphere with dark stripes.
Its surface of Venus is solid and like that of the Moon or Mercury, it is covered with mountains, basins, craters and faults. On the ground, the atmospheric pressure is 93 times higher than on Earth, which flattened all the reliefs as seen in the photos below.
The atmosphere of Venus is 96.5% carbon dioxide mixed with a little water vapor, oxygen, carbon monoxide and compounds based on sulfur, chlorine and fluorine. In summary, it looks like a polluted and acidic atmosphere that smells like rotten eggs!
The space probes also recorded dozens of lightning and storm rumblings in its atmosphere as well as winds blowing locally at 470 km / h, some clouds circling the planet in 4 days!
In addition, because of this thick atmosphere of carbon dioxide, it is horribly hot and the greenhouse effect is enormous: the ground temperature is on average 485° C (against ~ 15° C on Earth) but can go up to 900° C!
These temperatures and pressures are so extreme that even the metal-built spacecraft that visited Venus broke down after only one to two hours, probably broken or melted circuits!
Like Mercury, Venus is an unbearable planet, a torrid and inhospitable desert on which man will never set foot at the risk of losing his life.
Finally, like Mercury, one can witness transits of Venus in front of the Sun. This is a very rare phenomenon that occurs on average every 120 years. The last transit occurred on June 6, 2012 and the next will take place on December 11, 2117 and 2125. In short, none of us will be there to observe them.