|"Wow! This violent planet looks too violent for me. Dense clouds, and harsh surface extremes make this world a tough place to live."
Venus is the second closest planet to the Sun. It has no moon. With a diameter of 12104 kilometres, it is the closest in size to the Earth. Its orbit about the Sun takes 224.7 days with its mean distance from the Sun being almost three-quarters that of the Earth. Venus is the only planet that rotates retrogradely (which means that it rotates in a clockwise direction) in 243 days with respect to the stars (117 days with respect to the Sun, the Venusian day). A Venusian day is even longer than its year! From the Earth, the planet's surface is never seen as it is always covered by very dense layers of clouds.
Venus is always known to people as the twin planet of our mother earth. Venus is only slightly smaller than Earth (95% of Earth's diameter, 80% of Earth's mass). Both have few craters indicating relatively young surfaces. Their densities and chemical compositions are similar. Nevertheless, Conditions on these two planets were very much different. Scientist first thought that the thick continuous cloud cover of the Venus atmosphere is a good sign as it suggested moisture is present in large amount. Just like on earth, where every living organism depended on water for life, Venus was assumed that it could support life with all the water it had. Scientist often wondered if there was a vibrant Venusian world behind the thick cloud cover, overflowing with life.