Why does the Sun change position in the sky over different seasons?
The seasons are due to the motion of the Earth around the Sun.
So, it may not be surprising that the Sun's position in the sky
changes over seasons, due to the motion of the Earth around the
Sun. The explanation is simple. All stars in the sky are moving,
but the distant stars are so far away that we cannot detect
appreciable motion (even when the Earth moves around the Sun). As a
result, the positions of distant stars in the sky are fixed. At any
single moment the Sun can be projected as a dot onto the night sky
by extending the line that connects the Earth and the Sun (the line
of sight) all the way to the sky. As the Earth orbits around the
sun the line of sight changes direction and since the distant stars
are fixed in the sky, the position of the Sun with respect to the
distant stars changes.
The main factor that changes the Sun's position in the sky is
that the earth's axis of rotation is tilted. This means that the
sun is higher above the horizon in the summer months than in the