Ｑ４：	How dark is the sky in the total solar eclipse and annular solar eclipse ?

Ａ４：

When annular solar eclipse occurs, the sun's ray is still strong. Therefore the sky is blue and no stars can be seen. However, in total solar eclipse, the sky becomes dark. The darkness depends on the total solar eclipse and condition of atmosphere of the earth. If the atmosphere is clean, the sky becomes dark. If the atmosphere includes dusts, for instance, dusts from a volcano, the sky does not become so dark, since the dusts diffuse sun's ray. For example, at the total solar eclipse in eastern Australia in 1976, the sky has become too dark to see watches. People need lights to manipulate cameras. On the other hand, in the total eclipse in Mexico in 1991, the sky is not so dark, and people can read newspapers and watches easily. The reason why the sky was not so dark is considered as diffuse of ray by dusts from a volcano that had errupted in Philipine before the eclipse. The darkness depends on eclipses, in average it is almost the same as the sky of 20 or 30 minutes after the sun set. In this darkness, people can see planets and some bright stars.