In the solar system, the earth has 7 brothers and sisters, and they have different shapes and different "intimacy" with us . With the gradual depletion and deterioration of the earth's resources and environment, human beings gradually came up with the idea of ​​exploring and migrating to other planets. As our neighbors, Venus and Mars are the planets of choice.

From the perspective of distance alone, Venus is the closest to the earth , so according to the principle of saving fuel, humans should first land on Venus. However, judging from the current exploration planning and trends, human beings instead seek farther and farther, taking Mars as the first landing target. This behavior of choosing near and far seems very confusing, but in fact, it is because of the limitations of Venus' environment that humans make such a choice. So what secrets does the seemingly shining Venus have?

Beautiful and "brutal" Venus

Before we get to know the environment of Venus formally, let's take a look at its basic information. As one of the eight planets in the solar system, Venus is the closest to the sun. If it is sorted in this way, it should be the "sister" of the earth. Because of its unusual brightness, Venus was discovered as early as when the ancients were watching the sky at night, and for this reason, it was given many nicknames, such as Taibai, Qiming, Changgeng and so on.

Its English name is derived from Venus , the goddess of love in Roman mythology. Everyone must know the beauty of this goddess. It can be seen from the name that Venus was originally a very beautiful and mysterious planet in the eyes of human beings . People love Venus as much as the moon. After all, it can be seen from its brightness in the night sky that it is not an ordinary planet.

Under the exploration of the probes, the mysterious veil of Venus was slowly lifted by humans. Scientists were very happy when they discovered that Venus has a thick atmosphere before, because the existence of the atmosphere can effectively help the planet "lock in the temperature" , and this thermal insulation effect can allow life to be born and survive normally. To this end, there has also been a lively discussion in the academic world. Many scientists say that there should be lush rainforests and vast rivers under the atmosphere of Venus, where countless creatures live and survive .

Venus atmosphere

But the data sent back poured cold water on the enthusiastic people. The average surface temperature of Venus is as high as 464 ℃. Usually, the high temperature of more than 40 degrees in the summer of the earth makes many people unbearable. It is conceivable that the value of 40 times 11 times is more than 11 times. Maybe we have been dried or burned to ashes before landing. .

This is also the case. At first, the probes launched by humans took some pictures over Venus and have not yet descended into the atmosphere or directly reached the surface of Venus. So it's normal to watch the atmosphere fantasize about the surface of Venus. After all, we are too eager to find other life forms in the universe. After this, humans began to try to get the probe into the atmosphere of Venus, but it lost contact soon after it entered.

At first, everyone thought it was caused by a technical failure, but it was later discovered that it was affected by the harsh environment of Venus . Even if the probe is made of high-temperature-resistant metal, it cannot withstand the "baking" of Venus, so it should have disintegrated during the landing process. However, there are still successful landings, which will be introduced in detail in the second part.

In addition to the high temperature, Venus also throws out another cruel truth, that is, air pressure. The standard atmospheric pressure of Earth is 1013.25 hPa, while the surface atmospheric pressure of Venus is about 92 times that of Earth. If it is converted, it can be concluded that the pressure that humans bear when standing on the surface of Venus is equivalent to the pressure when they are 1,000 meters deep in the earth's ocean. At present, the deepest depth of human diving with equipment is 332 meters, which is basically the limit. On Venus, it is 1000 meters under the sea at any time, which is unbearable for human beings.

Therefore , although Venus is the closest to the earth among the eight planets, with a distance of about 40.5 million kilometers, it has also been directly removed from the visiting list by humans. The high temperature and high pressure doom us to be unable to land on Venus or to survive on it.

In addition, there may be many active volcanoes erupting on Venus, occasional sulfuric acid rain, or "giant winds" . Why is it called a hurricane, because the wind speed is higher than the 17-level wind on the earth. This means that even if it is landed, it will not "live" for long, and the spacecraft will be corroded or directly overturned and swept away.

So far, the "dream" of humans landing on Venus and the previous good conjectures about the atmosphere of Venus have been ruthlessly crushed after the actual data is returned. Therefore, there were always people who sighed at that time that Venus is a beautiful and cruel planet. It attracted us to explore with its beautiful appearance , but cruelly destroyed our idea of ​​landing and setting up camp with the real situation.

The exploration history of Venus

Even though Venus is now completely out of favor relative to Mars , it was still in the spotlight in the 1960s and 1970s . Both the United States and the Soviet Union have sent probes to Venus to investigate. Among them, the Soviet Union has been the most active. They have persevered in sending probes to Venus. Therefore, Venus has also been nicknamed the "Soviet Planet".

Between 1961 and 1983, the Soviet Union built a total of 16 Venus probes . The purpose of these probes varies, some orbit Venus to take pictures, while others directly reach the surface of Venus. We mentioned in the previous article that the interior environment of Venus is very harsh, so it is very difficult for probes to reach the surface of Venus.

Venus-7 , launched on August 17, 1970, completed this mission, successfully completing a soft landing on Venus. It is also that it sent data back to us for the first time, allowing humans to see the true appearance of Venus. No one thought that Jin Xing was not the weak woman who "bring rain with pear flowers" in everyone's imagination, but a devil with "hot temper".

However, the Soviet Union can be regarded as "very dedicated" to it. After learning about the harsh environment of Venus, everyone's interest in its exploration is not high, but the Soviet Union is still persistently sending probes to Venus. Even in 1975, Venus was given the first "gift" from human beings. Venus 9 and Venus 10, which entered the orbit, became the first pair of satellites of Venus. So far, this lonely "tempered" beauty also has own satellite.

The United States has always been less enthusiastic about Venus exploration, and successively launched the Mariner series, the Pioneer series and the Magellan spacecraft to take pictures and observe Venus . However, the highly skilled United States, although the number of launched probes is not large, it has made a lot of contributions to the detection of Venus. The most famous Magellan probe, for the first time, took a complete map of Venus and sent it back to Earth.

After entering the 21st century, human exploration activities for Venus have decreased significantly. However, in 2005, ESA still launched the "Venus Express" to the orbit of Venus for continuous exploration. In 2010, Japan also launched its own first Venus probe "Dawn", but these probes only made long-distance observations near Venus, and did not directly enter the atmosphere and land on the surface like the Soviet Union did.

In 2020, the Russian National Space Agency once again proposed the Venus exploration plan . In the future, they may join forces with NASA and ESA to further the Venus exploration program.

Why go to Mars?

Venus and Mars, as the neighbors of the earth, were chosen as the targets for exploration, both of which were related to distance in the first place. Although the distance between Mars and Earth is farther than that between Venus and Earth, it is still the best choice compared to other planets that are farther away.

Mars is one of the four terrestrial planets in the solar system. As a terrestrial planet, it is more similar to Earth. And, because of the fourth distance from the sun, it is still in the "habitable zone". After all, something that is too close like Mercury will always be scorched by the sun, and the position of Mars is relatively comfortable.

The closest distance between Mars and Earth is 55 million kilometers, which is within the acceptable range, although it looks particularly far away . Therefore, the distance is the main reason why we choose Mars as the detection target. Even if it is not as close as Venus, the harsh environment of Venus makes us have to settle for the next best.

Furthermore, scientists believe that the environment of Mars is more suitable for human immigration than Venus. The surface temperature of Mars is -63°C, which is unusually cold, but it is still much friendlier than the high temperature of 464°C. Because the metal of human-made detectors can withstand such low temperatures, but cannot withstand high temperatures. Moreover, human beings have also experienced the test of low temperature when they visited the moon before, and the experience of this will be more abundant.

In addition, the rotation period of Mars is very similar to that of Earth. It takes about 24 hours, 37 minutes and 22.7 seconds for one rotation, which is similar to the rotation of the earth, so if humans can immigrate to Mars in the future, it will be easier to "reverse the jet lag".

In short, Mars is very similar to Earth and is located in the habitable zone, so it is normal for it to be the target of human end-point detection. After all, with the development of future technology, we may be able to transform Mars and manually turn it into "Earth 2".

It can be seen that the choice to land on Venus or Mars must be based on the actual detection situation, and which side is easier and more valuable to detect is the primary influencing factor. For humans, Venus is currently a terrifying planet that cannot be landed. After all, probes can only last for more than 100 minutes. Our carbon-based creatures are afraid that they will be "ashes" as soon as they enter the atmosphere. Mars is friendlier and has fewer obstacles to landing than Venus.