Mercury’s average temperature has a wide range. In the daytime, its average temperature is 410 degrees Celsius, and in the nighttime, its average temperature is -170 degrees Celsius. Mercury’s atmosphere is thin. It is unstable, and extremely weak. Since Mercury is so hot, and because of Solar wind, atoms are continuously lost, and replenished by a variety of sources that humans probably would’t be able to survive in.

Venus's average Temperature is 470 degrees Celsius. Its atmosphere is made of mostly carbon dioxide. Several layers of clouds thick made of sulfuric acid block our view of Venus’s surface. Venus’s sky is streaked with lightning. Its dense atmosphere produces a run-away greenhouse effect that actually raises Venus’s surface temperature to a lot hotter. It would be hot enough to melt lead! Venus has strong winds about 350 kph at cloud tops. Winds at Venus’s surface are very slow; they are no more then a few kilometers per hour. Venus probably once had large amounts of water like Earth, but it probably boiled away because Venus is so close to the sun; Venus is now very dry.