Venus

Venus is a planet very similar to Earth. Venus is often called Earth’s sister planet, as the two are similar in size, mass, and composition.

The cover image shows an image of Venus, made with data recorded by the Japanese Akatsuki spacecraft in 2016.  Credit: PLANET-C Project Team / JAXA

Characteristics of Venus

In order of distance from the Sun, Venus is the second planet in the Solar System; and the fourth, in terms of size (from smallest to largest), if Pluto is considered as a planet.

Planets
Eight planets of the solar system Credit: Wikipedia

The planet surprised scientists with a chemical signature in its clouds. And in September 2020, the responsable of the Japanese robotic satellite, Akatsuki, reported the discovery of chemical phosphine (PH3) in the atmosphere of Venus.

If this information is confirmed, interest could be triggered to search for other signs of life floating high in the atmosphere of this beautiful planet.

When the brilliant science fiction writer Ben Bova wrote his magnificent novel “Venus” in 2000, the exploration of the planet by NASA and the USSR in the 40 years since 1961 had already revealed the main characteristics of Venus.

Planets size
Planets size Credit: web “universetoday.com”

Beauty of the planet Venus

The atmosphere of Venus is very thick and reflects much of the sunlight. That is why it is so brilliant.

Venus always shines in the morning or in the afternoon, like a beautiful jewel in the sky, announcing a new day or embellishing the sunset.

When visible in the night sky, Venus is the brightest object in the sky, apart from the Moon.

Venus evening
Sunset view at Paranal with Moon and Venus  Credit: ESO/Y.Beletsky, web “eso.org”

Venus can be seen only a few hours before sunrise (“morning star”) or after sunset (“evening star”).

It looks so wonderful in the sky that all civilizations have seen in it the goddess of beauty and love. It has been referred to as Aphrodite, Ishtar, Astarte, Inana, and Venus.

Sometimes it can be seen during the day, especially if the observer is located in a deep hole that limits the arrival of sunlight to his eyes.

Translation of Venus around the Sun

The movements of Venus in the sky were known to most ancient civilizations. The Mayan civilization developed a religious calendar based on the cycles of Venus.

Planets orbits
Orbits of the sun’s Planets  Credit: web “nationalgeographic.org”

The orbit of Venus is more like a circle than an ellipse. Its eccentricity is less than 1%.

Venus takes just over 224 Earth days to go around the Sun (Venusian year).

To make a complete turn on itself, it takes 243 Earth days (Venusian day) and turns counterclockwise, looking from the North Pole.

These two circumstances mean that if an astronaut were to live on Venus, they would see a sunset every 117 Earth days.

Also, you would see that the Sun rises in the West and sets in the East.

A Venusian year has 1.92 Venusian days.

Venus can get closer to Earth than any other planet.

On December 16, 1850, it was less than 40 million kilometers from Earth.

In the year 2101, it will be a little closer still, at 39.5 million kilometers.

In addition to rotating on itself slowly, in 1964 it was confirmed that Venus does it from East to West instead of West to East like the rest of the planets do (except Uranus).

From the surface of Venus, the Sun appears rising from the West and disappearing from the East.

The cause of the peculiar retrograde rotation of Venus is not known (it is speculated that it could be the result of a collision with an asteroid sometime in the remote past).

Its orbital and rotation periods are synchronized so that when it is closer to the Earth, it always presents us with the same face, as in the case of the Moon.

Venus north pole
The North Pole of Venus   Credit: SSV, MIPL, Magellan Team, NASA ;  web “nasa.gob”

Venus atmosphere

In the 19th century it was believed that the atmosphere of Venus had large clouds that concealed a water-rich world in which intelligent beings lived.

Some 20th century stories, such as “The Long Rain” (Ray Bradbury, 1950) and “The Illustrated Man” (Jack Smith, 1969), “The Oceans of Venus” (Isaac Asimos, 1954) describe Venus as a planet with water and habitable.

The reality is that its atmosphere is very dense, 95% of it is carbon dioxide (CO2), 4% is nitrogen and it has only small traces of oxygen.

This makes the pressure Venusian atmospheric pressure at surface level is 90 times the atmospheric pressure at the earth’s surface.

Solar radiation almost does not reach the surface of the planet as the dense layer of clouds reflects into space almost all the light from the Sun. That’s why Venus is very bright.

The light that manages to pass through the clouds of Venus is absorbed by them and causes an intense greenhouse effect.

Venus clouds
Clouds on Venus  Credit: web “universetoday.com

Venus is twice as far from the Sun as Mercury; therefore, it receives a quarter of the solar radiation.

However, Venus is hotter than Mercury, because the enormous amount of CO2 in its atmosphere causes a strong greenhouse effect that raises the temperature of the planet’s surface to around 460º C in the less elevated regions near the equator.

The surface of venus

Venust is the hottest planet in the solar system. It has two main plateaus like continents.

The northern plateau is about the size of Australia and contains the largest mountain on Venus (approximately 2,000 m higher than Mount Everest), called Mount Maxwell.

The southern plateau is larger than the previous one and has a size equivalent to that of South America.

The tectonic plates of Venus are thought to be not mobile like those of Earth, but rather fixed. Recent discoveries suggest that Venus is still volcanically active.

The interior of Venus is probably similar to that of Earth: an iron core about 3,000 km in radius, covered by a rocky mantle that appears to consist of recently solidified basalt, with very few meteorite craters.

Venus surface
The Venus Express probe completed eight years of mission on Venus. Credit: web “esa.int”

ESA’s Venus Express probe over six years has detected large variations in the concentration of sulfur dioxide in the atmosphere of Venus.

These changes could indicate recent volcanic activity in some of the hundreds of volcanoes that exist on the planet.

Venus sola paths
Solar Paths of 2004 and 2012 Venus Transit  Credit: NASA, web “nasa.gob”