Image courtesy: nasa.gov We all have heard or said the phrase, “…sure, when the Sun rises in the West”, to emphasize the impossibility of achieving or doing something. Ah, it is possible for the Sun to rise in the West. Not on Earth, but on Venus! Yeah! When viewed from above its North Pole, Venus rotates in a clockwise direction known as retrograde rotation, causing the Sun to rise in the West and set in the East. (Earth rotates in an anticlockwise direction from the viewpoint above its North Pole) Let’s see what else we can learn about Venus, the beautiful bright planet that we see at dawn during certain times and at dusk during other times of the year. The second planet from the Sun, and one of the four terrestrial planets, Venus is named after the Roman goddess of love and beauty. Sukhra is the Sanskrit name for Venus. Venus, is 108 million km from the sun, and is just a bit smaller in size than Earth with a radius of 6,052 km (Earth- 6,371 km) The planet is almost upright, tilting a mere 3 degrees; therefore there are no seasons on Venus. It has an iron core that is approximately 2,000 miles (3,200 kilometers) in radius. Above that is a mantle made of hot rock and a surface of very thin crust. The hot mantle, constantly heated by the interior heat churns slowly and constantly shifts. This shift causes the thin crust to bulge outwards resulting in volcanoes. There are tens of thousands of volcanoes on Venus. Venus' interior Image courtesy: space.com Orbit and rotation If there was a competition for the slowest rotating planet, Venus would win the first prize. Venus takes 243 Earth days to complete one rotation! It orbits around the sun in 225 Earth days in an almost circular path. Other planets’ orbits are elliptical. Although its rotation speed is slower than its orbital speed, because of retrograde rotation one day-night cycle on Venus takes 117 Earth days. Atmosphere While bright and beautiful to look at from Earth, Venus is not all that nice if we were to go and visit it. Venus’ environment is one of the most hostile and severely brutal The Venusian atmosphere is very thick and is made up of carbon dioxide and sulfuric acid. The Sun’s heat is trapped in this thick atmosphere resulting in temperatures above 470 degree Celsius that could melt lead. From Venus’s surface the day would like cloudy day on Earth. The atmosphere is so dense that if we stood on Venus it would feel like we are under one 1.6 kilometers deep underwater. That heavy. The weather is brutal with constant 220 mph sulfuric acid winds and rains. All the spacecraft that were sent to Venus have been damaged in a very short due to the high temperature and harsh acidic atmosphere. More than 40 spacecraft have explored Venus. The Magellan mission in the early 1990s mapped 98 percent of the planet's surface. Magnetosphere One would assume a magnetic field that is similar in strength to Earth’s around Venus because it’s almost same size and an iron core. However, due to its slow rotation, Venus’ magnetic field is very weak. Surface If, by some magic we survived the harsh Venusian atmosphere without burning up, and traveled the planet, we would see mountains, valleys, the tens of thousands of volcanoes and huge craters. These craters on Venus are all more than 1.5 kilometers across in diameter. That is because the smaller meteoroids burn up while travelling through the thick atmosphere and only large meteors survive to reach the surface creating impact craters. Viewing Venus For millions of years humans have observed Venus as the brightest object in the night sky. Venus orbits closer to the Sun (takes up the inner lane) than the Earth and has a smaller distance to take one “lap”. Venus takes almost 13 laps for every 8 laps that Earth makes, which is roughly once every 1.6 Earth years. However, we do not see Venus crossing the Sun because Venus’s orbital plane is slightly tilted, at about 3.4 degrees. What is orbital plane? Planets, comets, asteroids and other objects in the solar system orbit the sun. Imagine that the planets are travelling around the sun in the tracks of a stadium. Each planetary body takes up one lane in the track and stays there. This imaginary flat surface is called the orbital (elliptic) plane. Adding to the orbital plane is the different shapes of the two orbits – Earth’s elliptical and Venus’ almost circular. So for the majority of the time, whenever Venus passes between Earth and the Sun it is either above us or below us. Image courtesy: zoomschool.com Every once in a while Venus does touch Earth’s orbital level and that is when we see Venus passing the Sun. This is known as the “Venus transit”. Venus transits occurs in eight-year pairs and each pair occurrence repeats every 243 years. They pairs were observed in 1631 and 1639; 1761 and 1769; 1874 and 1882; 2004 and 2012. The next transit will be in December 2117. Below is the real time video of Venus' transit Venus transits are historically of great scientific importance as they were used to gain the first realistic estimates of the size of the Solar System. In 1627, Johannes Kepler predicted the 1631 Venus’ transit. It was Jeremiah Hocks who first recorded the 1639 transit. Information sources: Space.com, Universe today, NASA.
Wow very detailed and informative as always Kamala. Each time I know a little more about the rest of the planets and multitude of satellites and other stars and their planets..I only marvel a little more how special our earth is for sustaining life as we know it .!
Thank you @justanothergirl . True, I have never ceased to wonder if our existence is by fluke. The numerous factors that support our origin and existence has me dumbfounded always. Coming to Venus, this was one planet I was not happy writing. Learning how nasty a place it is, I felt sad about the popular saying " women are from Venus". I take it a huge insult. Every time I see this bright and beautiful glowing planet and knowing about its true nature, I always think how well the saying, "good from far, far from good" fits Venus to a T.
