The document discusses the Earth's rotation and revolution and how they cause day/night and seasons. The Earth rotates on its axis over 24 hours, causing day and night. It revolves around the Sun over 365.25 days, causing the seasons. The tilt of the Earth's 23.5 degree tilted axis relative to the Sun as it orbits results in the Sun being closer to the north or south tropic line during different parts of the year, bringing our summer and winter. Solstices occur when the Sun is directly overhead the Tropic of Cancer or Capricorn, with the longest and shortest days, while equinoxes happen when the Sun is directly above the equator.

1. Ch 24-2 Sun and seasons

2. Earth The Earth moves in two ways Rotation – the Earth’s spinning on its’ axis This causes day and night Takes 24 hours to complete Revolution – Movement around the sun This causes the seasons Takes 365 1/4 days to complete

3. Latitude Zones Latitude measures degrees north and south of the equator 0 degrees is equator, 90 degrees are the poles Three regions Tropics below 23.5 degrees north and south Temperate between 23.5 and 66.5 degrees Polar above 66.5 degrees

5. Seasons The Earth’s axis is tilted 23.5 degrees. As Earth orbits the sun its axis changes relative to the sun At some point the sun is closer to the north tropic line (our summer) and southern tropic (our winter) The seasons are caused by the tilt of the Earth’s axis as it moves around the sun.

7. Seasons Solstice occurs twice a year when the sun is directly overhead of 23.5 degrees June 21 summer solstice longest day of sun, December 21 winter solstice shortest day of sun Equinox occurs twice a year when the sun is directly above the equator. March 21 spring equinox, September 22 is Autumn equinox