The diameter of Venus is 12,104 kilometers. The earth is only slightly larger with a diameter of 12,742 kilometers.
The planet Venus
Venus is sometimes called the sister planet of the earth, but that only applies to the size and mass of the planet. On the surface, Venus is a glowing hot pressure cooker.
Venus is a rock planet and therefore has a solid surface, just like the earth. It is on average about 460 ° C hot on Venus, making it the warmest planet in the solar system.
The atmosphere of Venus
That heat comes from the sun and is retained by a very dense atmosphere. The atmosphere of Venus consists of 96 percent carbon dioxide, and therefore the planet has a very strong greenhouse effect.
Venus has no moons, but it has more than 1000 volcanoes with a diameter of 20 kilometers or more. For comparison: one of the largest volcanoes on earth, the Mauna Loa, has a diameter of 3 to 5 kilometers.
Press like at the bottom of the sea
Due to the thick atmosphere of Venus, the surface pressure is 92 times higher than on earth. This is comparable to the pressure that prevails at 900 meters below the sea. At the top of the Venus atmosphere is a layer of sulfuric acid clouds, making it impossible to observe the surface without radar.
What makes Venus rotate so slowly?
Venus is the only planet in the solar system where a day lasts longer than a year. A day on Venus, that is, a circle around its own axis, takes 243 earth days. On the other hand, a year on Venus, a circle around the sun, only lasts 225 earthly days.
And as if that wasn't strange enough, Venus 'turns around': the rotation around its axis is opposite to the rotation around the sun.
The diameter of Venus is 12,104 kilometers. The earth is only slightly larger with a diameter of 12,742 kilometers.© Shutterstock
This is probably due to the huge collisions in which Venus was involved, just like the earth and the other planets, when the solar system was only recently created. There were many more planets at that time, constantly bumping into each other.
Possibly Venus initially rotated in much the same way as the earth and the rotation was slowed down by a huge collision with another planet.
Probes cannot withstand the environment on Venus
Since the beginning of the space age era, probes have been coming to Venus. It is even the first planet visited by a space probe. Already in 1961 the Russians sent a probe to Venus, but the American Mariner 2 made the first measurements.
But it is not easy to get close to Venus. Because the sunlight there is almost twice as strong as on earth, the equipment must be cooled in a probe, otherwise it would not survive the heat.
And with a possible landing on Venus, the problems really start.
The dense atmosphere is full of carbon dioxide, creating a greenhouse effect. It can reach 480 ° C. Moreover, the pressure is 90 times as high as on the earth's surface.
As a result, it is already a major achievement to keep a probe that has landed on Venus working for an hour.
The surface of Venus is mapped by probes in orbit around the planet and consists of a dry desert landscape with sharp rocks. Occasionally the soil is renewed by lava from volcanic eruptions.© Shutterstock
Probes map Venus from a job
But a solution is being worked on. Astronomers are now able to study the surface of Venus without landing on it.
A number of reliable maps have already been made with the help of radar, and a probe such as the Venus Express, currently orbiting the planet, can 'see' the surface to a certain extent by observing light of certain wavelengths .
The surface of Venus consists - as we know thanks to the Venus Express - from a dry desert landscape with sharp rocks. Occasionally the soil is renewed by lava from volcanic eruptions.
As a next step, balloons could be brought into the thick clouds around Venus. This way, researchers can find out if there are micro-organisms in the clouds, where it is not as warm as on the surface.© Shutterstock
Living on Venus
Due to the high average temperature on Venus of 464 ° C, life (as we know it) is unlikely to occur on Venus. But when we look back a few billion years in time, Venus was probably a habitable planet with a mild temperature, gentle winds and rolling seas as we know it from the earth.
That's what a group of scientists from the Planetary Science Institute in Tucson, in the US, think. Using simulated climate models that take into account factors such as day length and solar energy, they discovered that Venus was probably habitable until three billion years ago.
And these scientists are not the only ones who think so. For years, researchers have been suggesting that Venus had a more pleasant climate in the past: the size of the planet resembles the earth and Venus is largely made of the same rock.
However, one factor can throw a spanner in the works: the new climate models assume that Venus used to run at the same speed as today, and the evidence for that is still lacking.
Ray: 6052 km (0.95 times the earth) Mane: 0 Distance to the sun: 108 million km Temperature: 460 ° C (aver.)