In some ways, Venus is similar to earth. It is about the same size as the earth, has a nickel-iron core, and has volcanic activity due to radioactive heating in the interior. But that is where the similarities end. Venus has some serious problems as a vacation spot - mainly that it is extremely hot and the atmosphere is a thick cloud of sulfuric acid, CO2 and other unpleasant chemicals.
So how did Venus get to be like that, and why is the earth different?
- Venus is closer to the sun, which makes it hotter and prevents formation of oceans due to excessive evaporation.
- Venus suffered a traumatic collision in it's early days, which causes it to rotate very slowly and parallel to the ecliptic. This makes for long afternoons (thousands of hours long) which get extremely hot.
- Because of 1 and 2, Venus was never able to sequester CO2 in limestones like the earth.