Earth and Sun

Earth rotates on its axis once every 24 hours, receives light when facing the sun (day), circle of illumination, night is shadow side, length of day is most extreme near poles, most consistent near the equator

Seasons

Rotation axis of the Earth is tilted 23½ ° away from perpendicular to plane of ecliptic; The north pole always points to the North Star (Polaris); one pole is facing toward the sun while the other pole is tilted away from the sun; the N pole faces the sun when the sun is between the Earth and the North Star, but faces away from the sun when the Earth is between the sun and the North Star.

solstices, June 21 and Dec 21, direct rays on Tropic of Cancer or Capricorn (23 ½ N), 24 hours of light or dark above Arctic circle and Antarctic Circle; equinoxes, March 21 and Sept 22, direct rays on equator, 12 hours of day and night, equal everywhere

Length of Day

tilt of rotation axis and circle of illumination; long in summer, short in winter (solstice); 12 hours in spring and autumn (equinox)

Explain why the Earth has seasons and why they are opposite in the northern and southern hemispheres. When is Earth closest to the sun and when is it at its greatest distance from the sun?

Compare and contrast the solstices and equinoxes in terms of: time of occurrence, location of most direct sun rays, effect on hours of daylight, relative position of Earth, Sun and North Star