Colonization of Venus
Venus's atmosphere is made mostly out of carbon dioxide, which, after filtering from sulfuric acid, can be used to grow food. Because nitrogen and oxygen are lighter than the carbon-dioxide that makes the atmosphere, breathable-air-filled balloons will float at a height of about . At this height, the temperature is a manageable ; or if we could get higher (see ).
Maat Mons
Intriguingly for planetary geologists, atmospheric studies carried out by the Pioneer Venus probes in the early 1980s revealed a considerable variation in the concentrations of sulfur dioxide (SO) and methane (CH) in Venus' middle and upper atmosphere. One possible explanation for this was the injection of volcanic gases into the atmosphere by plinian eruptions at Maat Mons.