Transit of Venus
I hadn't really prepared for this, but when I looked at the clouds I went back to sleep. To be fair, however, nothing was as good as these images
I don't normally bother about the details of the structure of the sun although it is, of course, very important to life on earth.
In 1999 we went to Cornwall to see the eclipse of the sun (Lunar) and indeed it was very cloudy, it got very dark and then light again. Still quite a nice trip though.
The Venusian Transit and associated geometry is an interesting part of history. Some of the astronomers took real efforts to measure the transit. Worth a look at on the net.