This day is a solar term in the northern hemisphere.

(1) After this day, the days in the northern hemisphere began to be shorter than the nights, so this day is the autumn equinox in the northern hemisphere.

(2) On the vernal equinox, the world is divided into day and night on average.

(3) In the picture, the terminator line is a weak line from day to night; Dark lines coincide with warp circles; The relationship with latitude is vertical.

(4) local time of the faint line 18 o'clock. According to "the east is early and the west is late, and the east is added and the west is reduced", the local time at point B is 16.

(5) The local time on the faint line is 18 o'clock, and the Beijing time is 10 o'clock, according to "East early and west late, East plus West minus".

So the answer is:

(1) Autumn Equinox.

(2) The length of day and night is equal.

(3) weak lines; Coincidence; Vertical.

(4) 16.

(5) 10.