We have eight planets in our solar system and each one revolves around the sun at a different distance. Planets vary in temperatures as they vary in structure and distance from the sun. Temperatures are influenced by the distance of planets from the sun and as the distance increases, the temperature decreases. There is basically an inverse relationship between distance and temperature. Both interior and exterior factors are responsible for temperature variations within the planets. Earth is the third planet and the temperature and climate here are just appropriate for living a life. Here in our Solar System, there are planets both hotter and colder.
So which one is the hottest?
You might think its Mercury because it is closest to the Sun and therefore gets more direct heat. As Mercury completes an orbit around the Sun in just 88 Earth days, it achieves a maximum temperature of 700 Kelvin (427 °C / 800 °F) at its hottest, equatorial locations during the day. Due to its extremely slow rotation, Mercury spends a considerable amount of time in a dark, shielded state, where its night side drops to just 100 Kelvin. That is a very cold temperature, and far lower than any known natural temperature on Earth.
But although Mercury is hot, Venus is hotter.
And now you might be thinking why Venus is hotter than Mercury, if Mercury is closer to the sun?
The answer to it lies in the fact that Venus has an extremely dense atmosphere made up of various gases like carbon dioxide, nitrogen, and sulfuric acid, while Mercury has a very thin atmosphere with various gases, but very little carbon dioxide. Carbon dioxide plays a vital role because sunlight will pass through Venus clouds which contain mostly carbon dioxide and warm the surface of the planet. Usually, the surface of a planet is warmed during the day and cools off at night by releasing infrared radiation back into space. But the carbon dioxide in Venus clouds absorbs energy from infrared radiation very well and “traps” the heat on the planet, making it very warm. This has been called a “runaway greenhouse effect.” It doesn’t happen on Mercury because its atmosphere is not thick and does not have much carbon dioxide in it.
Now as we come to know that Venus is the hottest planet in our solar system. Let’s find out more details about the planet:
1) Origin
Venus is the second planet from the sun and the hottest in the solar system. It is popularly recognized for the Roman goddess of love and beauty. Venus is the only planet named after a female that may have been named for the most beautiful deity of her pantheon because it shone the brightest of the five planets known to ancient astronomers.
In ancient times, Venus was often thought to be two different stars, the evening star, and the morning star, the ones that first appeared at sunset and sunrise. In Latin, they were respectively known as Vesper and Lucifer. In Christian times, Lucifer, or “light-bringer,” became known as the name of Satan before his fall. However, further observations of Venus in the space age show a very hellish environment. This makes Venus a very difficult planet to observe from up close because spacecraft do not survive long on its surface as it is so hot that even lead melts.
2) Physical Characteristics
Venus is a terrestrial planet and is sometimes called Earth’s “twin sister planet” because of their similar size, mass, proximity to the Sun, and bulk composition. It is the hottest world in the solar system. Its temperatures can reach 464ºC. The high temperatures are due to a dense atmosphere with a thick cloud cover. Carbon dioxide makes up the bulk of the planet’s atmospheric gasses thus act as a blanket that keeps heat from escaping the planet. Venus has the same temperature at all times, day or night, at an average of 735 Kelvin (462 °C / 863 °F) In contrast to other planets, its small elliptical tilt of 3º does not affect temperatures, allowing them to remain steady.
Venus has a very dry surface. It has been kept in a prolonged molten state by its long-term exposure to ultraviolet rays. Water would immediately boil away due to the extreme heat created by the ozone-filled atmosphere on its surface and thus its atmosphere does not have any liquid water. Over two-thirds of Venus is covered by flat, smooth plains with a number of active volcanoes that are up to more than 3,000 miles wide, with lava flows carving deep, winding canals.
About one-third of Venus’ surface is covered by mountainous regions. One of those regions, Maxwell, is 540 miles (870 kilometers) long and reaches almost 11 kilometers in height, making it the highest place on the planet.
Scientists think that over 1,600 volcanoes are present on Venus’ surface, but there are most likely many more too small to see from Earth. Most of these volcanoes are dormant, though a few are still active.
Venus is at an extremely high pressure – about 90 times higher than the pressure at sea level on Earth, which is like the pressure on the surface of the ocean about half a mile (1 km) below the surface.
3) Orbital Features
Venus rotates on its axis the opposite way that most planets rotate. That means on Venus, the sun would appear to rise in the west and set in the east. On Earth, the sun appears to rise in the east and set in the west. So basically they both act opposite each other in this case.
In the Venusian year time taken to orbit the sun is about 225 Earth-days long. Normally, that would mean that days on Venus would be longer than years. However, because of Venus’ curious retrograde rotation, the time from one sunrise to the next is only about 117 Earth-days long. Venus has a magnetic field more than 0.000015 times smaller than Earth’s due to its sluggish spin which makes it impossible to create a magnetic field like that of the Earth.
4) Orbit & Rotation
The Average distance of Venus from the sun is 67,237,910 miles (108,208,930 km) and if we do comparison it is 0.723 times that of Earth. The closest approach to the sun called Perihelion and is about 66,782,000 miles (107,476,000 km) and by comparison, it is 0.730 times that of Earth. The farthest distance from the sun is called Aphelion and is about 67,693,000 miles (108,942,000 km) and by comparison, it is 0.716 times that of Earth
5) Composition & Structure
The Atmospheric composition of Venus by volume is 96.5 percent carbon dioxide, 3.5 percent nitrogen, with minor The Atmospheric composition of Venus by volume is 96.5 percent carbon dioxide, 3.5 percent nitrogen, with minor amounts of sulfur dioxide, argon, water, carbon monoxide, helium, and neon. The Internal structure of Venus’ metallic iron core is roughly 2,400 miles (6,000 km) wide. Venus’ molten rocky mantle is roughly 1,200 miles (3,000 km) thick. Venus’ crust is mostly basalt and is estimated to be 6 to 12 miles (10 to 20 km) thick on average.
6) Climate & Atmosphere
Venus has an extremely dense atmosphere that consists of various gases such as carbon dioxide, nitrogen and sulfur dioxide that covers the cloud completely. Carbon dioxide makes up the bulk of the planet’s atmospheric gasses thus acting as a blanket that keeps heat from escaping the planet. The temperatures are regular throughout the year with slightly negligible variations. In contrast to other planets, its small elliptical tilt of 3º does not affect temperatures, allowing them to remain steady. The very top layer of Venus’ clouds zip around the planet every four Earth-days, propelled by hurricane-force winds traveling roughly 224 mph This super-rotation of the planet’s atmosphere, some 60 times faster than Venus itself rotates, maybe one of Venus’ biggest mysteries. The winds at the planet’s surface are much slower, estimated to be just a few miles per hour.
A long-lived cyclone on Venus, first observed in 2006, was observed in constant flux with elements constantly breaking apart and reforming. The clouds also carry signs of meteorological events known as gravity waves, caused when winds blow over geological features, causing rises and falls in the layers of air.
Unusual stripes in the upper clouds of Venus are called “blue absorbers” or “ultraviolet absorbers” because they strongly absorb light in the blue and ultraviolet wavelengths. These are soaking up a huge amount of energy nearly half of the total solar energy the planet absorbs. As such, they seem to play a major role in keeping Venus as hellish as it is. Their exact composition remains uncertain and some scientists suggest it could even be life, although many things would need to be ruled out before accepting that conclusion.
7) Is There Life on Venus?
The moon Enceladus, the planet Mars, and even the moon Titan are currently the places to search for signs of extraterrestrial life. However, a breakthrough scientific discovery in 2020 led scientists to wonder whether they could find life in the current hellish atmosphere of Venus.
Scientists now believe that Venus may have been habitable billions of years ago, and fairly similar to Earth today. Venus’ surface temperature has soared since that time, and its atmosphere is described by many as ‘hellish’ due to a drastic greenhouse effect.
A strange chemical found in the clouds of the planet in 2020 has some scientists thinking it’s a sign of life: phosphine. This is a compound found both on Earth and on Jupiter and Saturn. Scientists believe it could appear in Venus’ atmosphere for very short periods of time, similar to how it does on Earth.
However, what does this phosphine discovery have to do with the search for life?
As well as being used as rat poison, phosphine has been found in the bodies of some microorganisms and some scientists speculate that microbes actually produce the compound on Earth.
This has led some scientists to suspect that, if microbes are capable of creating phosphine, then perhaps microbes are responsible for phosphine in the atmosphere of Venus. Following the discovery, further analysis has raised some doubt about whether the compound was created by microbes, but scientists are still investigating, especially with new missions being planned for the planet.
