What part of Earth is darkest at the solstice? Why?

1 Answer
Jul 19, 2016

At summer solstice (around Dec 21), there is no sunrise for latitudes > #66.6^o N#. Likewise,..at winter solstice ( about June 23 ), there is no sunrise for latitudes > #66.6^o S#...

Explanation:

When the angle of incidence of sunlight rays is# >90^o#, for the

whole day of 24 hours,#, there is no sunrise.for the day.

At summer and winter solstices, the angles of incidence of rays of

sunlight will be # >=latitude +- 23.4^o#

Accordingly, at summer solstice (around Dec 21), there is no sunrise

for latitudes > #66.6^o N#.

Likewise,..at winter solstice ( about June 23 ), there is no sunrise for

latitudes > #66.6^o S#...

In the fringe latitudes above these limits, there will be twilight. In the

interior on these spherical caps, it will be darkest. The sun will not

rise above the horizon at all..
..