Path of the Sun Around the Sky

As the earth moves around its orbit, we see the sun in front of different constellations. In January the sun is in front of Sagittarius, but by March it has moved along the ecliptic into Aquarius. The ecliptic is the projection of the earth's orbit onto the celestial sphere.

(b) On the day of the winter solstice, sunlight strikes the ground at a steep angle and spreads out. Thus, the ground receives less energy per square meter from the winter sun than from the summer sun.