Expert: Philip Stahl - 2/19/2008

Question
why does venus have clouds? what are the clouds made of? have astronauts bin to saturn and venus

Answer
Hello,

The clouds on Venus were probably formed soon after the planet itself. Some surmise, however, that the atmosphere -clouds only changed much later due to a "runaway Greenhouse effect". Perhaps  Venus even had some small proportion of oxygen- but over time carbon dioxide dominated and increased.

Basically, the present day Venus has an atmosphere that is about 96% carbon dioxide (compared to less than 0.03% for Earth) and 3% Argon with traces of water vapor.

The clouds reach up nearly forty miles from the surface- with the lower clouds mainly of CO2 and the upper level clouds (yellowish white) composed of sulphuric acid mixed with some water vapor. (Sulphuric acid is the type used in car batteries)

No astronauts have have been to Saturn or Venus, but there have been Russian space craft (unmanned) that have crashed on Venus' surface and recorded temperatures, conditions before melting. (The temperature on the surface is over 470 C, or over 800F.

I don't believe Venus is a place that any sane astronaut would wish to visit!