Venus is hotter than Mercury due to its thicker atmosphere. The greenhouse effect refers to the heat trapped by the atmosphere. If Venus did not have an atmosphere, its surface temperature would be 128 degrees Fahrenheit, far cooler than Mercury's typical temperature of 333 degrees Fahrenheit.
However, because of its atmosphere, most of Venus is covered in sulfuric acid rain that destroys any spacecraft that lands on it. Even if it weren't for this reason, scientists would still want to avoid landing on Venus due to its high temperatures. Landings on Mercury are possible but very dangerous because of its very small size and proximity to the Sun. The solar radiation on Mercury is about 3 times that of Earth!
Also see: Mercury vs. Venus vs. Earth.
Venus has a dense atmosphere that retains heat. Venus is hotter than Mercury because it has a carbon dioxide atmosphere and a lot of volcanic activity. Earth's neighbor also has high levels of sulfur dioxides in its air.
The average temperature on Venus is 483 degrees Fahrenheit (270 degrees Celsius). Although this may not seem that hot to us, it would kill anyone who went outside on the planet immediately. The surface is covered by a thick layer of sulfuric acid rain which would destroy any living organisms that might be found there.
Only one planet, Mercury, is left in our solar system that has a thin atmosphere. Because of this, scientists think that if life ever developed on Mars, it would most likely be based on what they know about Venus.
Cirrus clouds are seen in the atmosphere of Venus at certain times of the year. These clouds are made out of carbon dioxide and exist at very high altitudes, between 60 and 100 miles (100-150 km) above the surface. They are only visible from certain angles with the Sun behind you, when they block out part of the sunlit side of Venus.
The cloud cover on Venus is always changing, so observers on Earth see things like clouds or no clouds over the planet.
The reason Venus is hotter than even Mercury is due to its thick, dense cloud cover, not its position in the solar system. Venus is the closest planet to Earth in terms of size and mass, yet its atmosphere produces large temperature disparities between the two worlds. Earth's atmosphere prevents most of the sun's heat from reaching the ground by blocking out most of the light emitted by the star. The atmosphere also acts as a thermal blanket, preventing our planet from heating up too quickly after forming.
However, because Venus has no way to escape the influence of the sun, it receives nearly all of its energy from him. Even though it is almost half as big as Earth, with twice as many atoms for its mass, Venus is still too hot for life as we know it. It is estimated that there is more water vapor in the atmosphere of Mars than on Earth, although this may be due to Martian soil being wet rather than being full of water itself. If so, then Mars would be able to support life as we know it.
Earth's moon is another example to show that not all planets need to have an atmosphere to have living things. However, since Venus doesn't have any oceans to speak of, this shows that Earth's atmosphere is what keeps our planet cool enough for life as we know it. Without this protective layer, average surface temperatures would be about 50 degrees Celsius (120 degrees Fahrenheit).
The majority of the heat from the sun is trapped by carbon dioxide. Cloud layers also serve as a blanket. As a result of the "runaway greenhouse effect," the planet's temperature has risen to 465 °C, hot enough to melt lead. As a result, Venus is even hotter than Mercury.
Venus and Mercury are both planets that orbit the Sun, but they differ greatly in size. Venus is about 72 percent larger than Earth and orbits closer to the Sun than we do. Mercury is only slightly smaller than Earth and orbits even closer to the Sun than Venus does. This difference in distance from the Sun causes them to be exposed to different levels of sunlight throughout their cycles of day and night.
Because Venus is so much larger than Mercury, it absorbs more solar radiation. This heating effect is called "solar inflation." In addition, the thicker atmosphere of Venus traps this energy within its body, giving it another reason to glow red.
Mercury has no significant internal source of heat to balance out its loss of heat through radiation into space. So, like Earth, it must chill itself down at night when the solar radiation drops off. But because it is so close to the Sun, there is not enough time for all of its surface water to freeze during winter. Instead, large regions of ice remain visible from Earth year-round.
With an average temperature of 880 degrees Fahrenheit, Venus is the hottest planet in our solar system. Despite the fact that planetary temperatures tend to rise with increasing closeness to the sun, Venus is actually warmer than its neighbor, Mercury, for a variety of reasons. The thick atmosphere of carbon dioxide traps heat from the sun and prevents it from escaping into space.
Earth's average temperature is 57 degrees Fahrenheit. Water covers 71 percent of the planet's surface, so it's no surprise that most of Earth is also water—with a few exceptions. Antarctica is frozen soil covered by ice thousands of feet deep, and it doesn't receive any sunlight to heat up like other places do during the day. The only organisms that can survive there are bacteria that use the carbon in the soil as their source of energy and food.
The next three planets out in order of distance from the sun are Mars, Jupiter, and Saturn. All of them have very thin atmospheres because they're made mostly of gas, so they don't block out much light. This means they experience daily cycles of warming and cooling but on average would be cold enough to freeze water into ice.
Uranus and Neptune are the only two planets that aren't made of rock or ice. They're composed mainly of hydrogen and helium, which are the most common elements in the universe.