Humanity is accelerating the exploration of space, and 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 Venus 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 can see 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, it is certainly Venus.
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, humans have launched over 40 spacecraft to Venus, of which 11 launches were unsuccessful, 7 spacecraft failed to approach, and only 9 probes managed to get close to this planet. This is also why we know very little about the surface of Venus.
The atmosphere of Venus
If you look at Venus through a telescope, you will see it does not have the reddish-yellow hue shown in images; in fact, that color is a false representation hypothesized by astronomers, as no one knows the true color of this planet’s surface.
Typically, we see Venus surrounded by a thick atmosphere, as shown in the image below from NASA’s MESSENGER mission. We can see that Venus is covered by clouds with seemingly no gaps.
This is the image of Venus we can see through a telescope.
If you use an infrared camera to photograph near Venus, you will get a different view of this planet.
The Venus probe Akatsuki uses an infrared camera to capture images of Venus’s sun-facing side.
This means that the atmosphere of Venus is flowing at a breathtaking speed, in fact, wind speeds can reach up to 300 km/h.
The atmospheric mass of Venus is 93 times greater than that of Earth. With Venus being nearly the same size as Earth, the atmospheric pressure on the surface of this planet is over 90 times greater than that of Earth, equivalent to the pressure found at a depth of 1 km below sea level on our planet.
In the dense atmosphere of Venus, carbon dioxide makes up 96.5%, with the remaining 3.5% being nitrogen and trace gases such as sulfur dioxide, water vapor, and sulfuric acid droplets.
Because carbon dioxide is a greenhouse gas, such a dense atmosphere brings extremely high temperatures to the surface of Venus. The average surface temperature of this planet reaches 462 degrees Celsius, hot enough to melt lead, much hotter than our typical 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 convection of Venus’s atmosphere and the dense carbon dioxide’s strong thermal inertia.
The average surface temperature of this planet reaches 462 degrees Celsius.
Venus is so hot that all astronaut suits or landers made by humans would melt upon landing on its surface. Therefore, to this day, Venus remains our most mysterious “neighbor.”
Why is Venus so hot?
In fact, billions of years ago, Venus did not resemble what it is today. It once had vast oceans, and its environment was even more suitable for life than Earth at that time.
Billions of years ago, Venus did not resemble what it is today.
When the Solar System began to form, there was a large amount of debris, asteroids, and wandering planets. However, under the influence of the Sun’s gravitational force, they collided with the planets in the closest orbits for millions of years.
Accordingly, Venus was continuously impacted, preventing it from rotating from west to east like other planets, causing it to rotate in the opposite direction at a very slow speed.
Thus, on Venus, the Sun rises in the west and sets in the east; a day on Venus lasts 243 Earth days, while this planet takes only 224.7 Earth days to complete its orbit around the Sun. Therefore, one 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 the planet is losing its magnetic field.
A day on Venus is longer than a year on this planet.
Worse still, strong impacts from celestial bodies have broken 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 oceans to evaporate. Consequently, the greenhouse effect spiraled out of control, and the planet became increasingly hotter.
Water vapor in the atmosphere could not be retained for long, and Venus lost the protection of its magnetic field, making it unable to withstand solar radiation. Solar winds and ultraviolet rays would photolyze water molecules in the atmosphere, breaking them down into hydrogen and oxygen, which were then blown into space. A few remaining water molecules in the atmosphere would combine with sulfur dioxide to form sulfuric acid hydrates, creating sulfuric acid clouds in Venus’s atmosphere.
Venus lost the protection of its magnetic field, making it unable to withstand solar radiation.
The magnetic field of Venus
Astronomers have two differing views about Venus’s magnetic field. One view suggests that Venus’s core has completely solidified, condensing with the mantle, and the rising temperature of the mantle reduces the heat flow from the core, preventing it from generating a “dynamo effect.” Therefore, Venus has no magnetic field.
The other view posits that Venus’s core remains a completely liquid “ocean” of iron, with the entire core having nearly similar temperatures, lacking temperature differentials, thus failing to create convection and generate a magnetic field.
Although both viewpoints are speculative, their conclusions are the same: Venus does not have a magnetic field like Earth.
Venus does not have a magnetic field like Earth.
In fact, there is still a weak magnetosphere surrounding Venus. However, this magnetosphere is not created by Venus’s magnetic field; rather, it is generated through the interaction between the ionized layers of Venus’s atmosphere and solar winds. This magnetosphere provides negligible radiation protection for Venus’s atmosphere, allowing 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. Simultaneously, 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.
