# which fraction of the solar radiation corresponds the blocked part by Venus at its transit upon he sun?

Well, asumming that Venus orbits the Sun at 0.7233 AU and its diameter is 12,104 km, I can conclude that its angular diameter seen from the earth is ~1', then its represents ~1/31 part of the angular diameter of solar disc, so that's represents only $$1365Wm^{-2}/31 ~ 44 Wm^{-2}$$ , hence that fraction represents just ~ 44/1365 ~ 0.0322... of the total radiation.

Did I reason correctly?

• I think you have wrongly compared the ratios of the angular diameters, rather than the ratio of the area of the disks? So calculate ratio of pi*(angular radius)^2 for Venus/Sun... would give you a much smaller fraction. Oct 11 at 20:50
• @lucas Ohhhh I get it, I get it, I passed off the fact that I was looking for the area of the disks Oct 11 at 21:04