We explain what Venus is, its location in the solar system and its dimensions. Also, what are its characteristics, its climate and geological composition.
What is Venus?
Venus is a planet in the solar system, the second closest to the Sun and the third smallest. It is a rocky and terrestrial planet, similar in size, mass and composition to those of Earth. However, its atmosphere and temperature present conditions that do not allow the development of life.
It has a diameter just smaller than the Earth, and has volcanoes and mountains on its surface, just like our planet. Due to the high concentration of carbon dioxide in its atmosphere, Venus has very high temperatures, exceeding 450 °C, making it the hottest planet in the solar system.
Venus has been observed by humanity since ancient times, since it is one of the three stars that can be distinguished with the naked eye during the day (along with the Moon and the Sun). Since it appears after sunset or at dawn, it has been called the “morning star,” and is part of many poetic compositions, traditional astrological theories, and ancestral calendars.
The name Venus comes from Roman mythology. The choice of the name for the planet responds to the fact that Venus is one of the brightest and most visible objects in the sky, and its luminosity is particularly notable during sunrise and sunset. Therefore, ancient civilizations associated this shiny object with the goddess of love and beauty, and gave it her name: Venus.
Characteristics of Venus
The main characteristics of Venus are:
- It is the third smallest planet in the solar system.
- It is the second closest to the Sun, after Mercury.
- It is the closest planet to Earth and is similar in size.
- Almost all of its atmosphere is made up of carbon dioxide.
- It is the warmest planet in the entire solar system.
- Its rotation is slower than its translation, so the days are longer than the years.
- Its oldest rocks are approximately 800 million years old.
- It has no known moons.
- It rotates on its axis in the opposite direction to most other planets.
Location and dimensions of Venus
The orbit of Venus is located between those of Mercury and the Landabout 108 million kilometers from the Sun. It is the second closest planet to the Sun and the one closest to Earth.
Going around the Sun takes 225 Earth days, and rotating on its own axis takes 243 days. This is a distinctive feature of Venus, since, due to its slow rotation, the days are longer than the years.
It has a diameter of 12,104 kilometers, which makes it the planet most similar in size to Earth.. Due to its size, proximity and similar rock composition, Venus is known as the “sister” planet of Earth.
Composition of Venus
Almost the entire surface of Venus is made up of basalt, an igneous rock that reaches the surface as a result of volcanic eruptions.. This happens due to the intense volcanic activity that Venus has always had throughout its geological history.
In addition, it is characterized by having very few craters due to meteorite impacts. It is believed that this could be due to the characteristics of its atmosphere, which does not allow the arrival of objects from space due to its high density and temperature.
It is estimated that its oldest rock formations would not exceed 800 million years old, making it a relatively young planet compared to Earth.
Regarding the most significant surface structures, Venus has two large continental plateaus, elevated above a wide plain: Ishtar Terra in the north and Aphrodite Terra in the south.
Venus atmosphere
The pressure and temperature of Venus are extremely high, due to the characteristics of its atmosphere.composed mostly of carbon dioxide (96%). This pressure is ninety times greater than that of the Earth and its average temperature is 460°C (hotter than Mercury, despite being twice as far away from the Sun).
In addition to carbon dioxide, the Venusian atmosphere contains other minor gases, such as nitrogen, sulfur dioxide, carbon monoxide, argon, helium and neon. This dense layer of greenhouse gases traps heat and contributes to raising surface temperatures.
Explorations to Venus
The main explorations that were carried out on Venus to know its characteristics were:
- Mariner 2. It was launched in 1962 and was the first spacecraft to approach Venus. It was the first to directly measure the temperature of another planet and confirm the high temperature in the atmosphere of Venus.
- Mariner 5. It was launched in 1967 and also made a close encounter with Venus. It provided more data about the planet's atmosphere and surface conditions.
- Mariner 10. It was launched in 1973 and made several orbits around Venus before heading to Mercury. Although it was not designed specifically for Venus, it passed by this planet and made some valuable observations.
- Pioneer Venus 1. It was launched in 1978, and included an atmospheric probe that descended to the surface of Venus and an orbiting probe that studied the planet's atmosphere.
- Pioneer Venus 2. This mission included multiple atmospheric probes that were launched toward Venus in 1978, penetrating the atmosphere and transmitting valuable data during their descent.
- Magellan. Also known as Venus Radar Mapper, it was a NASA mission launched in 1989. It was an orbiter that used radars to map the surface of Venus and provided detailed images of the planet.
- Venus Express. It was a probe launched by the European Space Agency (ESA) in 2005 to study the atmosphere and surface of Venus. The mission ended in 2015.
- Akatsuki. It was launched by the Japan Aerospace Exploration Agency in 2010. It entered the orbit of Venus in 2015 and has since provided detailed climate information on the planet's atmosphere.
Curiosities of Venus
Venus presents some peculiarities, among them:
- Retrograde rotation. Venus is one of the few planets in the solar system that undergoes retrograde rotation. This means that it rotates in the opposite direction to most other planets.
- The days are longer than the years. The time it takes for Venus to orbit the Sun is shorter than it takes to rotate on its own axis, so a day on Venus is longer than a year.
- The extreme greenhouse effect. Venus' dense atmosphere contributes to an extreme greenhouse effect, making its surface temperatures the highest of any planet in the solar system. It is even hotter than Mercury, despite being further from the Sun.
- The absence of moons. Venus has no known moon, unlike most other planets in the solar system.
- The light of Ashen. Ashen light is a phenomenon that takes place in the nocturnal half of Venus, that is, the sector that does not shine on it from the Sun. It consists of a yellowish halo of light that was observed for the first time in 1643 and has not yet been observed. has managed to explain its origin.
References
- GeoEncyclopedia. (2022). Venus. https://www.geoenciclopedia.com/
- NASA Science. (2021). All about Venus. https://spaceplace.nasa.gov/
- Rodríguez, H. (2023). Venus, Earth's scorching twin planet in the solar system. National Geographic Spain. https://www.nationalgeographic.com.es/
