Venus is Earth’s closest planetary neighbor and the second planet from the Sun. It’s one of the four inner, terrestrial (or rocky) planets, and it’s often referred to as Earth’s twin due to its size and density. However, these are not identical twins; there are significant differences between the two worlds. Venus has a thick, toxic atmosphere filled with carbon dioxide, and it is perpetually shrouded in thick, yellowish clouds of sulfuric acid, which trap heat and cause a greenhouse effect. Even though Mercury is closer to the Sun, it is the hottest planet in our solar system. Surface temperature of Venus is around 900 degrees Fahrenheit (475 degrees Celsius), which is hot enough to melt lead. The surface is a rusty color, with intensely crunched mountains and thousands of large volcanoes. Scientists believe that some volcanoes may still be active. At its surface, Venus has crushing air pressure – more than 90 times that of Earth – comparable to the pressure found a mile below the ocean on Earth. In this article, we will have a closer look at the atmosphere of Venus.
Why is Venus so hot?
You may have heard that Venus is the hottest planet in the solar system. Indeed, the surface of Venus is hot enough to melt lead. But why is Venus so scorching? Runaway greenhouse effect is a three-word phrase. In many ways, Venus is Earth’s virtual twin. It is similar in size, mass, gravity, and internal composition. However, one significant difference is that Venus has a much thicker atmosphere. If you could stand on the surface of Venus, you’d feel 93 times the atmospheric pressure we do here on Earth; to feel that pressure, you’d have to dive 1 km beneath the surface of ocean. Furthermore, that atmosphere is almost entirely composed of carbon dioxide.
Carbon dioxide, as you’ve probably heard, is an excellent greenhouse gas, trapping heat from the Sun. The atmosphere of Venus allows sunlight to pass through the clouds and down to the planet’s surface, where it warms the rocks. However, the clouds prevent the infrared heat from the warmed rocks from escaping, causing the planet to warm up. The average temperature of Venus is 735 kelvin, or 461° C. In fact, the temperature is the same all over Venus. It doesn’t matter if you’re at the pole or at night; the temperature is always 735 the same.
Plate tectonics on Venus are thought to have ceased billions of years ago. And because plate tectonics did not bury carbon deep within the planet, it was able to accumulate in the atmosphere. Carbon dioxide accumulated to the point where any oceans on Venus boiled away. The hydrogen atoms were then carried away from Venus by the solar wind of sun, making it impossible to ever make liquid water again. Carbon dioxide concentrations continued to rise until they were all present in the atmosphere.
Why Venus is hotter than mercury?
As we all know that the first planet from sun is Mercury and then Venus comes. Then obviously, one thinks that as Mercury is closer to sun so definitely, it will be the hottest planet in the solar system. But it is not true. The hottest planet in solar system is Venus, but how it can be possible? The answer is that Venus has a dense atmosphere composed of carbon dioxide, nitrogen, and sulfuric acid, whereas Mercury has a thin atmosphere composed of various gases but very little carbon dioxide. So, what’s the big deal about carbon dioxide? So, sunlight will pass through the clouds of Venus (which are mostly carbon dioxide) and warm the planet’s surface. Typically, a planet’s surface warms during the day and cools at night by releasing infrared radiation (heat) back into space. However, the carbon dioxide in Venus’ clouds absorbs a lot of energy from infrared radiation and “traps” the heat on the planet, making it very hot. This is sometimes referred to as a runaway greenhouse effect (as mentioned above). We don’t see this happen on Mercury because its atmosphere is not thick and does not have much carbon dioxide in it.
Is life possible on Venus?
Is there any possibility of life on Venus? Because of Venus’s proximity and similarities to Earth, the possibility of life on Venus has piqued the interest of astro-biologists. To date, no definitive evidence of past or present life has been discovered. In the early 1960s, spacecraft studies revealed that the current Venusian environment is extreme in comparison to Earth’s. Studies continue to be conducted to determine whether life could have existed on the planet’s surface prior to the onset of a runaway greenhouse effect, and whether a relict biosphere could have survived high in the modern Venusian atmosphere.
With extreme surface temperatures approaching 735 K (462 °C; 863 °F) and an atmospheric pressure 90 times that of Earth, Venus’s conditions make water-based life as we know it on the planet’s surface unlikely. In recent years, scientists have come to regard Venus, the second planet from the sun, as a possible home for life. Modeling studies, for example, have suggested that ancient Venus had large oceans and a pleasant climate that could have lasted billions of years. Of course, Venus is famously hellish today; its surface is bone-dry and hot enough to melt lead. However, some scientists believe that if life ever existed on Venus, it could still exist there, floating in the clouds about 30 miles (50 kilometers) up, where temperatures and pressures are similar to what we experience at sea level here on Earth.
Why Venus is called Earth twin?
This is due to the fact that Venus and Earth are nearly the same size, have roughly the same mass (weigh about the same), and have a very similar composition (are made of the same material). They are also close neighbors. However, Venus and Earth are not exactly same. Venus has an atmosphere that is about 100 times thicker than Earth’s and extremely hot surface temperatures. Venus does not have life or oceans of water like Earth. Another significant difference between Earth and Venus is that Venus, unlike the majority of the other planets in the solar system, rotates on its axis backward. This means that the Sun rises in the west and sets in the east on Venus, the opposite of what we experience on Earth. (It’s not our solar system’s only planet with an unusual rotation; Uranus also do same.)
Facts about Venus
- Venus was the first planet to be explored by a spacecraft and was heavily researched early in the history of space exploration. Venus was also the first planet visited by an Earth-based spacecraft. Because of the extreme heat, landers have only survived for a few hours.
- Venus is the second closest planet to the Sun, orbiting at about 67 million miles (108 million kilometers).
- Venus rotates on its axis very slowly – one day on Venus lasts 243 Earth days. However, because Venus orbits the Sun faster than Earth, one year on Venus takes only about 225 Earth days, making a Venusian day longer than its year.
- Venus is permanently shrouded in thick, toxic sulfuric acid clouds that begin at an altitude of 28 to 43 miles (45 to 70 kilometers). The air smells like rotten eggs!
- In comparison to the other planets in our solar system, Venus rotates backward on its axis. This means that, contrary to what we see on Earth, the Sun rises in the west and sets in the east.
- After the Moon, Venus is the second brightest natural object in the night sky. The sulphuric acid clouds in Venus’ atmosphere reflect and shine, obscuring our view of its surface. Its brightness allows it to be seen even during the day – if the sky is clear and you know where to look.
- Venus has 90 times the atmospheric pressure of Earth, which is roughly equivalent to the pressure found at 1km depth in the Earth’s oceans.
- Venus has more volcanoes than any other planet in the solar system. Astronomers have identified over 1,600 volcanoes on its surface, but there are likely many more that are too small for us to see. Scientists believe that the majority of these are dormant, though a few may still be active.
- Venus appears to have phases like the moon because it orbits the sun within Earth’s orbit. When Venus is on the opposite side of the sun, it is in full phase, whereas when it is between the Earth and the sun, it is in new phase. In 1610, Italian astronomer Galileo Galilei was the first to witness these phases.