qAt present-day, the axis is
tilted at an angle of 23.5°, referred to as Earth’s “obliquity”,
or “tilt”.
qThe Sun moves back and forth
through the year between 23.5°N and 23.5°S.
qEarth’s 23.5° tilt also defines the 66.5° latitude
of the Artic and Antarctic circles. No sunlight reaches
latitudes higher than this in winter day.
qThe tilt produces seasons!!