Long term temperature effects of an eclipse I was surprised to see a very measurable difference in temperature at my home during the recent solar eclipse.  The temperature was about 93 degrees fahrenheit but dropped to around 86 degrees.  It made me wonder how an unusual eclipse might affect a planetary body.


If there were a situation where someone had put an object into a stable synchronous orbit that would block a percentage of solar radiation, how big would it have to be for an appreciable effect?  An example would be from Futurama's Crimes of the Hot episode Wernstom's giant parabolic mirror that reflected 40% of all sunlight.
If an effect similar to a solar eclipse would be prolonged over a specific area, how would that effect the local atmosphere?  I would assume it would create a stable "cold front" in that area.  Is there any information on how that would affect other passing cold or warm fronts?
It was suggested that we could cool down Venus by putting a powder cloud in the Lagrange point between it and the Sun. This will cool Venus in a few months to the point where its atmosphere will start liquify, creating a global CO2 ocean. The surface of an ocean is much easier to colonize than creating flying cities.