Venus

Venus (pronounced /'vi?n?s/) is the second-closest planet to the Sun, orbiting it each 224.7 Earth days. It is the brightest usual object in the night sky, except for the Moon, reaching an obvious magnitude of -4.6. Because Venus is a substandard planet, from Earth it never appears to venture far from the Sun: its elongation reaches a maximum of 47.8°. Venus reaches its maximum brightness shortly before sunrise or shortly after sunset, for which reason it is frequently called the Morning Star or the Evening Star.

Classified as a terrestrial planet, it is now and then called Earth's "sister planet", for the two are similar in size, gravity, and bulk composition. Venus is enclosed with an opaque layer of highly reflective clouds of sulfuric acid, preventing its surface from being seen from space in visible light; this was a subject of great speculation until some of its secrets were exposed by planetary science in the twentieth century. Venus has the densest atmosphere of all the terrestrial planets, consisting frequently of carbon dioxide, as it has no carbon cycle to lock carbon back into rocks and surface features, nor organic life to take up it in biomass. It has become so hot that the earth-like oceans the young Venus is supposed to have possessed have completely evaporated, leaving a dusty dry deserts cape with many slab-like rocks. The evaporated water vapor has dissociated and hydrogen has runaway into interplanetary space. The atmospheric pressure at the planet's external is 92 times that of the Earth, the great mass of it carbon dioxide and other greenhouse gases.