Hi Raoul

Mars & Venus were both big let downs.

No one expected Venus to be so damned hot and wrapped in so much atmosphere prior to the early 60s. At worst Venus was imagined as a boiling hot desert with formaldehyde dust clouds, but otherwise not insuperably hostile.

Mars was expected to have a bit more atmosphere - though John Campbell guessed about 100 Pa back in 1937 -, but the biggest disappointment was the disconfirmation of the seasonal colour changes being a sign of life. Almost everyone was convinced that was vegetation - Carl Sagan was banking on it in a National Geographic article as late as 1967, and discussed it in "Intelligent Life in the Universe".

Even the Galilean satellites eventually proved a disappointment - no atmospheres, bathed in radiation - and a surprise, with their sub-surface oceans. And Titan... has no decent views of Saturn.

*sigh*

Adam