The Earth’s Tilt n n n The Earth is tilted on its axis at 23. 5 degrees For 6 months the Northern Hemisphere is tilted towards the sun and for the next 6 months the Southern Hemisphere is tilted towards the sun This is the cause for the seasons
Solstices/Equinox Summer Solstice-June 22 nd, Maximum amount of daylight for the Northern Hemisphere n Autumnal Equinox-September 22 st, Equal amount of sunlight for both Hemispheres n Winter Solstice-December 22 st, Maximum amount of daylight for the Southern Hemisphere n Vernal Equinox-March 22 st, Equal amount of sunlight for both Hemispheres n
Precession n Precession is the change in the orientation of a rotating axis n n The angle remains constant but the direction of the axis changes Would not affect Earth’s Seasons but would affect what stars are seen at night
Nutation n Nutation is the wobbling that occurs around Earth’s axis which changes the angle about ½ of a degree every 18 years n Happens due to the gravitational pull of the moon
Barycenter n A barycenter is the center that 2 objects orbit around. n n When the moon orbits a planet both bodies orbit around a point in the middle This point is closer to the larger body
Barycenter n The sun does not remain motionless in the solar system. n Due to the pull of the planet’s gravity the sun orbits a barycenter in the solar system