After learning about our solar system, definitely one question rises in your mind: “Why is Venus hotter than Mercury?”
Earlier, when you first heard about this theory, it sounded wrong to you. Because in our solar system, Mercury comes first, and it is closest to the sun. Venus comes after Mercury. According to the position of Mercury in the solar system, it should be the hottest planet. Then why is Venus hotter than Mercury?
This fact isn’t a mistake. It is real and one of the most exciting facts in planetary science. It makes us realize, “What we see is not always the truth; sometimes the science behind it is very strange.” Let us explore the science behind this fact in this article.
Understanding the Basic Difference Between Venus and Mercury
Before understanding the fact “Why is Venus hotter than Mercury?” you should learn about the basic difference between the planets, Mercury and Venus. Mercury and Venus are both planets with rocky surfaces, but they behave completely differently in many ways.
Mercury
- Mercury comes in first position in our solar system.
- It is closest to the sun.
- Mercury has no atmosphere.
- Mercury is extremely hot during the daytime and extremely cold during the night time.
Venus
- Venus comes after Mercury in second position in our solar system.
- Venus has a very thick atmosphere, and most of the atmosphere is made of dense carbon dioxide.
- Venus’s atmosphere contains about 96% of carbon dioxide (CO₂).
- Venus’s atmosphere is about 90 times thicker than the earth’s atmosphere.
- Venus is always covered with the dense clouds made of sulfuric acid.
- Venus is farther away from Mercury, but still Venus is much hotter than Mercury.
The Real Reason: Why Is Venus Hotter Than Mercury?
The main reason for “why Venus is hotter than Mercury” is the greenhouse effect. The greenhouse effect is responsible for the extreme heat on a planet. In this effect the atmospheric gases (like carbon dioxide (CO₂), methane, water vapor, etc.) trap the heat and do not let the heat escape out of the planet. This process makes the planet’s temperature high.
But in the case of Venus, it is worse. As I told you before, Venus’s atmosphere is very thick and mostly made of carbon dioxide. So, when the sunlight enters Venus’s atmosphere. It gets absorbed by the surface. This energy tries to go back into space, but carbon dioxide traps this heat and does not let the heat escape. The heat is trapped again and again in the atmosphere. This makes Venus the hottest planet of the solar system. If water once existed, it gets evaporated and becomes water vapor. Water vapor is also a strong greenhouse gas, which makes the heating process even worse. This heating process never stops. Scientists call it a runaway greenhouse effect.
Mercury is the closest planet to the sun, but it is not the hottest planet in our solar system because it has no atmosphere. So it does not show any greenhouse effect and is also not able to trap any heat. That’s why Mercury experiences extreme heat during the day time and extreme cold during the night time. But Venus has an intense atmosphere and constant intense heat. This makes it the hottest planet. This is the main reason for “Why is Venus hotter than Mercury?”
Scientists found underground lava tubes on Venus
Mercury and Venus’s Surface Temperature
Venus has a thick heat-trapping atmosphere, so it has extremely high temperatures all the time. The average Venus surface temperature is around 460°C (860°F). This temperature is high enough to melt lead. Venus’s temperature does not cool down at night like the earth’s. It has a dense atmosphere that acts like a blanket, and it is mostly made of carbon dioxide that traps the heat. Venus has almost the same temperature during day and night.
Mercury gets extremely hot, but it cannot hold the heat because it has no atmosphere. During the daytime its temperature rises up to 430°C (800°F). But when the sun sets, all the heat goes back to space, and its temperature drops up to -180°C (-290°F) at night because Mercury has nothing to trap the heat. Lack of atmosphere creates a big difference in the temperature between Venus and Mercury. This is the big reason for “Why is Venus hotter than Mercury?”
Why Distance From The Sun Is Not Enough
Many people think closer to the sun means the hottest planet. But this is only partially true. Only the distance from the sun does not decide which planet is the hottest one. A planet’s atmosphere plays an important role in deciding its temperature. Closer to the sun only controls how much sunlight enters the planet’s surface. If the planet is not capable of trapping the heat, then all heat escapes to space, and it does not affect the planet’s temperature more. Like Mercury, it’s the closest to the sun, but it has no atmosphere to trap the sunlight. So all heat goes back to the space, and its temperature cools down at night. On the other hand, Venus is farther from the sun, but it is much hotter than Mercury because it has a very thick and dense atmosphere that traps the sunlight. Mercury and Venus are the perfect examples of “Why is the distance from the sun not enough?” This explains why is Venus hotter than Mercury despite being farther from the sun.
Venus’s Clouds Make The Heat Even Worse
Venus is covered by the clouds made of sulfuric acid. These clouds make the heat even worse because they play a very essential role in trapping heat. These clouds act as a barrier and do not allow the sunlight to escape from the planet. These clouds act like an insulating layer that sends back the heat that rises from the surface. These clouds are made of sulfuric acid. They reflect some of the sunlight but trap a large amount of heat inside the atmosphere. These clouds cover the whole planet and also prevent it from cooling down at night. Venus’s clouds are another reason for “Why is Venus hotter than Mercury?”
What Scientists Learn From Venus
Venus teaches scientists how a planet like Earth evolves in an extreme way. Scientists can understand the greenhouse effect. By studying the runaway greenhouse effect, scientists can learn how to trap heat, evaporate oceans, destroy natural habitat, change climatic conditions, and make a planet overheat all the time. Earlier some theories suggested that Venus may once have had an ocean and an Earth-like atmosphere. But with time carbon dioxide increases in the atmosphere, the ocean gets evaporated, and the greenhouse effect spirals out of control. With the help of recent studies, scientists learn about the lava activity and planetary geology of Venus. It has underground lava tubes. Venus is like a scientific laboratory where scientists can understand how environment, heat, and geology together make the planet’s condition worse.
Conclusion
In this article we discuss all about “why is Venus hotter than Mercury?” Venus comes after Mercury, but instead of Mercury, Venus is the hottest planet in the solar system. This is because Mercury has no atmosphere, while Venus has a thick atmosphere mostly made of dense carbon dioxide. Heat is trapped in the atmosphere on Venus, while Mercury does not hold heat. So Venus is hotter than Mercury. I explained the whole concept above in detail. Closer to the sun does not mean that it is able to trap heat as well. By studying my article, you’ll understand why is Venus hotter than Mercury.