Definitely not Venus

The place: the planet Venus. The date: September 1999 16 small spacecraft will leave the mother spacecraft and land in different areas on the planet, which are almost the size of the Earth. On their way to the ground they will measure the air pressure and the temperature in the layers of the atmosphere

The place: the planet Venus. The date: September 1999 16 small spacecraft will leave space from the mother spacecraft and land in different areas on the planet, which are almost the size of the Earth. On their way to the ground they will measure the air pressure and the temperature in the different layers of the atmosphere.

These will be the first spacecraft to reach Venus since the landing of the "Magellan" spacecraft in 1991. Similar to Magellan, these spacecraft will also not be able to operate for a long time after reaching the ground, due to the great heat prevailing on the star (about 500 degrees Celsius), the high atmospheric pressure (90 atmospheres, like the pressure in the sea at a depth of 1,000 meters) and mainly - due to its acidic composition, which digests many substances.

For many years, astronomers saw the planet Venus as a twin star to Earth; Until the early 1991s, many believed that it was covered in water. However, American and Russian spacecraft that landed on Venus in 1962-XNUMX made it clear that it is not a twin star but at most an ugly sibling, very far from Venus, the goddess of love and beauty, after which the Romans named the star.

Venus is indeed the third brightest star in the solar system - after the sun and the moon - but its surface is hidden by clouds and cannot be viewed from Earth. It seems that this is why the astronomers preferred Mars, which is smaller. Today, however, scientists realize that the planet Venus may provide important information about the future of Earth. A phenomenon similar to the greenhouse effect occurs in Nega, and the expansion of knowledge about this process may help solve the problem on Earth.

In an article about Nega recently published by the British magazine "Focus" a description of the star is presented. About two-thirds of its surface is flat, and the rest of the surface has mountains, valleys and craters. About a million volcanoes are scattered all over the planet. The lowest point in its territory, called the Diana depression, is two kilometers deep, much deeper than the Grand Canyon on Earth. The highest point is the Maxwell Mountains, which rise to a height of 11 kilometers.

The sky of Venus is gray because of the clouds. Lightning storms worship the sky at a rate of 24 lightnings per second. The atmosphere of Nega consists of 96% carbon dioxide and 3.5% nitrogen. Sulfuric acid clouds drop pure acid rain, but this rain never reaches the ground because it evaporates due to the high temperature.
Scientists wanted to understand why the rotation of the planet Venus on its axis is opposite to the direction of rotation of the Earth and most of the other planets.

Until recently, it was thought that the phenomenon took place under the influence of the earth. Venus revolves around the Sun three times in 729.27 days, and Earth does so twice in 728.5 days. The scientists hypothesized that due to the similar rotation ratio (3:2) the Earth causes Venus to rotate in the opposite direction. But the astronomers finally concluded that the Earth's gravitational forces are not strong enough to cause this. Today it is believed that the reason why the planet rotates around its axis in the opposite direction lies in the past.

Venus was formed - like the Earth and the other planets - from the merger of small planets that floated in the space of the solar system. Apparently one of those asteroids orbited the Sun in the opposite direction to the direction of Venus, and they collided. The planet merged into Venus, but changed the direction of its rotation, so that Venus now rotates from east to west, meaning that the sun rises in the west and sets in the east of the planet after 243 Earth days.

Has Venus always been a planet that has no life on it, and life cannot exist on it? Four billion years ago, the Sun emitted only about 70% of the radiation it emits today, and the greenhouse effect in Nega was much weaker. The scientists believe that its surface was then only XNUMX degrees warmer than the Earth's surface today. Several types of bacteria and microorganisms such as those that live in hot springs on Earth could exist under these conditions. But even if these creatures did exist (and there is no certainty about this), they must have disappeared after the intensity of the sun's radiation increased greatly and the greenhouse effect became stronger. The scientists speculate that in about two billion years, when the sun's heat rises, the earth will follow the Venus. Prepare the air conditioners.

The article was published by me in "Haaretz" on January 20, 1999