Humanity is accelerating the process of space exploration; in the future, we will land on Mars. However, Venus is much closer to our planet. So why, until now, has there been no project to send humans to Venus?
The English name for this planet is Venus, which is also the name of the goddess of love and beauty in ancient Roman mythology. But if you observe and study this planet, you will find that it is not beautiful and romantic as its name suggests. This is a planet with an extremely harsh climate, hot enough to be compared to hell. Therefore, if you are looking for a “hellish” planet in the Solar System, Venus is undoubtedly it.
From left to right are Mercury, Venus, Earth, and Mars; we can see that Venus is nearly the same size as our planet.
Landing on Venus is not easy
Since the 1960s, humanity has launched over 40 probes to Venus, with 11 failed launches, 7 spacecraft failing to approach, and only 9 probes able to get close to this planet. This is also the reason why we know very little about the surface of Venus.
The Atmosphere of Venus
If you observe Venus through a telescope, you will see that it does not have the reddish-yellow hue as shown in the images; in fact, that color is a simulation by astronomers, as no one knows the true color of the surface of this planet.
Typically, we see Venus has a thick atmosphere as shown in the image below, captured during NASA’s MESSENGER mission. We can see that Venus is covered by clouds and seemingly has no gaps.
This is an image of Venus as seen through a telescope.
If you use an infrared camera to capture images near Venus, you will get a different view of this planet.
The Akatsuki probe uses an infrared camera to capture images of Venus facing the Sun.
This indicates that the atmosphere of Venus is flowing at a staggering speed, with wind speeds reaching up to 300 km/h.
The atmospheric mass of Venus is 93 times that of Earth. Given that Venus is nearly the same size as Earth, the atmospheric pressure on its surface is more than 90 times that of Earth, equivalent to the pressure at a depth of 1 km below sea level on our planet.
In the thick atmosphere of Venus, carbon dioxide makes up 96.5%, while the remaining 3.5% consists of nitrogen and trace gases such as sulfur dioxide, water vapor, and sulfuric acid droplets.
Since carbon dioxide is a greenhouse gas, such a dense atmosphere leads to extremely high temperatures on the surface of Venus. The average surface temperature of this planet reaches 462 degrees Celsius, hot enough to melt lead, much hotter than our usual furnace temperatures. Even at the northern and southern poles of the planet, temperatures remain above 450 degrees Celsius day and night. This is due to the extremely high convective nature of Venus’ atmosphere and the dense carbon dioxide having strong thermal inertia.
The average surface temperature of this planet reaches 462 degrees Celsius.
Venus is so hot that all the astronaut suits or landers made by humans would melt upon landing on its surface. Therefore, until now, Venus remains one of our most mysterious “neighbors.”
Why is Venus so hot?
In fact, billions of years ago, Venus was not at all like it is today. It once had vast oceans and even its environment was more suitable for life than Earth at that time.
Billions of years ago, Venus was not at all like it is today.
When the Solar System began to form, a large amount of debris, asteroids, and wandering planets existed. However, under the influence of the Sun’s gravitational force, they collided with the planets in the closest orbit over millions of years.
Accordingly, Venus was continuously bombarded, preventing it from rotating from west to east like other planets, and instead, it rotates in the opposite direction at a very slow speed.
Thus, on Venus, the Sun rises in the west and sets in the east, with a day on Venus lasting 243 Earth days, while this planet takes only 224.7 Earth days to complete its orbit around the Sun. Therefore, it can be said that a day on Venus is longer than a year on this planet. This means that Venus hardly rotates on its own, its core has also stopped moving, and this planet has gradually lost its magnetic field.
A day on Venus is longer than a year on this planet.
Worse still, the strong impacts of celestial bodies have shattered the outer crust of Venus, and continuous volcanic eruptions have released carbon dioxide and sulfur dioxide from the ground into the atmosphere, resulting in a greenhouse effect that caused all the oceans to evaporate. Consequently, the greenhouse effect spiraled out of control, and this planet became increasingly hotter.
The evaporated water in the atmosphere could not be retained for long, and as Venus lost its magnetic field, it could not resist the invasion of solar radiation. Solar winds and ultraviolet rays photolyze water molecules in the atmosphere, breaking them down into hydrogen and oxygen, which are then blown into space. A few remaining water molecules in the atmosphere combine with sulfur dioxide to form sulfuric acid hydrates, creating sulfuric acid clouds in the atmosphere of Venus.
Venus loses its magnetic field, making it unable to resist the invasion of solar radiation.
The Magnetic Field of Venus
Astronomers have two different perspectives on the magnetic field of Venus. One perspective suggests that the core of Venus has completely solidified, which has condensed with the mantle, and the temperature of the mantle increases, reducing the heat flow from the core, preventing it from generating a “dynamic effect.” Therefore, Venus has no magnetic field.
The other perspective suggests that the core of Venus remains a completely liquid iron “ocean,” with the entire core having nearly uniform temperature, lacking temperature differences, making it impossible to form convection and generate a magnetic field.
Although both perspectives are hypothetical, their conclusions are the same: Venus does not have a magnetic field like Earth.
Venus does not have a magnetic field like Earth.
In reality, there is a weak magnetosphere around Venus. However, this magnetosphere is not generated by Venus’ magnetic field; instead, it is created through the interaction between the ionosphere of Venus’ atmosphere and solar winds. This magnetosphere provides negligible radiation protection for Venus’ atmosphere, which allows water to continuously decompose and be blown into space. Consequently, this planet is no longer suitable for life.
Why is the atmosphere of Venus still preserved?
Solar radiation can dissociate water, but it does not have enough energy to break down carbon dioxide, sulfur dioxide, and sulfuric acid. At the same time, volcanic activity on the surface of this planet has continuously pumped carbon dioxide and sulfur-containing gases into the atmosphere for billions of years, allowing these gases to continue to increase.
