Our Sister-Planet is a perfect example of the consequences of a runaway greenhouse effect. Nearly the size of our planet but completely inhabitable for life as we know it.
A Bit of History
The exact date for Venus’s discovery is unknown as it was discovered thousands of years ago and has been a part of many cultures here on Earth. It is the only planet in our solar system to be named after a female(Roman goddess of Love and Beauty).
The majority of study of the planet started in the 1960s with the Soviet Venera program shortly joined by United States’ Mariner 2 mission on 14 December 1962. On October 18, 1967, the Russian probe Venera 4 entered venus’s atmosphere, and in 1975, Venera 9 and 10 lander missions captured black and white images of the surface. Seven years later, the first colored images were obtained from Venera 13, and Venera 14 landers.
Place in the Solar System
The second planet in our solar system orbits the Sun at an average distance of about 108 million km and completes one orbit in 225 days. It takes Sunlight 6 minutes to reach the planet at this distance.
Venus and Uranus are the only two planets in the solar system that rotate backward on their axis(Clockwise). It is also the slowest rotating planet(Speed at the Equator: 6.5 km/hr), with one complete rotation in 243 Earth days which makes it a nearly perfect spherical shaped planet. This results in, one Venusian year being 1.72 times one Venusian solar day.
Venus’s Atmosphere
The Yellow planet is actually a runaway greenhouse effect with over 96% of its atmosphere consisting of Carbon dioxide and only 3.5% Nitrogen. This huge amount of CO2 in the climate absorbs and traps the heat from the Sun and as a result, Surface temperatures reach up to 470 degrees celsius(Hotter than the closest planet to the Sun: Mercury). This temperature remains the same at the equator and the poles of the planet.
The atmosphere is very dense with 93 times the mass and 92 times the pressure we experience here on Earth. Above the thick layer of CO2, are clouds made of sulphuric acid which blocks the sunlight from reaching the surface of the planet, scattering or reflecting 90% of the light. The wind speeds at these cloud tops can be as high as 360 km/hr.
Venus’s Surface
Much like Earth, Venus has mountains and valleys with a dusty landscape. It has thousands of volcanoes and some of them are active as observed by ‘Venus Express’(Venus exploration mission by ESA) in the form of transient infrared hot spots. The surface is also covered by thousands of evenly distributed impact craters. But the size of the craters is no smaller than 2 km across. Because of the dense atmosphere, the projectiles lesser than 50 m in diameter and without certain kinetic energy simply burn up into the atmosphere unable to create craters on the surface.
Key Facts
A day on Venus is longer than a year! It takes 243 Earth days to complete 1 rotation while it orbits around the Sun in 225 Earth days.
We can experience the same pressure on the surface of Venus by diving about 1 km into oceans here on Earth.
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