Earth's Rotation, Revolution, and Seasons

• Earth's rotation is its spin on its axis.
• Earth rotates counterclockwise when viewed from above the North Pole.
• Earth's rotation causes us to experience day and night.
• Revolution refers to Earth's orbit around the Sun.
• Earth revolves counterclockwise around the Sun.
• Earth's revolution results in the cycle of seasons.
• One rotation takes approximately 24 hours to complete.
• Completing one revolution takes 365.25 days.
• Earth's axis refers to an imaginary line passing through the North and South Poles, around which Earth rotates.
• Earth's axis is tilted at an angle of 23.5 degrees relative to its orbital plane.
• The primary reason for experiencing seasons is the tilt of Earth's axis.
• Winter in the Northern Hemisphere: the Northern Hemisphere is tilted away from the Sun.
• Summer in the Northern Hemisphere: the Northern Hemisphere is tilted towards the Sun.
• During summer, daylight hours are longer.
• Conversely, daylight hours are shorter during winter.
• Diagram Labeling:
• #18: Summer or winter
• #19: Day or night
• #20: Summer or winter
• #21: Orbital path
• #22: Axis
• #23: Day or night

Seasons Diagram Analysis:

• Summer Solstice:
• Position in Diagram: A/D
• N. Hemisphere Date: June 21st
• S. Hemisphere Date: Dec. 21st
• Daylight vs. Night: More daylight
• Autumnal Equinox:
• Position in Diagram: A/B
• N. Hemisphere Date: Sept. 21st
• S. Hemisphere Date: March 21st
• Daylight vs. Night: Approximately equal
• Winter Solstice:
• Position in Diagram: C/D
• N. Hemisphere Date: Dec. 21st
• S. Hemisphere Date: June 21st
• Daylight vs. Night: Less daylight
• Vernal Equinox:
• Position in Diagram: A/B
• N. Hemisphere Date: March 21st
• S. Hemisphere Date: Sept. 21st
• Daylight vs. Night: Approximately equal

Positions of Earth:

• Position H: Earth experiences winter in the Northern Hemisphere.
• Position F: Earth experiences summer in the Northern Hemisphere.
• Position G: Earth experiences fall in the Northern Hemisphere.
• Position I: Earth experiences spring in the Northern Hemisphere.
• Position F: Earth experiences winter in the Southern Hemisphere.
• Position H: Earth experiences summer in the Southern Hemisphere.
• Position I: Earth experiences fall in the Southern Hemisphere.
• Position G: Earth experiences spring in the Southern Hemisphere.

Uncommon Terms:

• Solstice: either of the two times in the year, the summer solstice and the winter solstice, when the sun reaches its highest or lowest point in the sky at noon

• Equinox: the time or date (twice each year) at which the sun crosses the celestial equator, when day and night are of equal length (about September 22 and March 20).

• Vernal: connected to spring.

• Autumnal: connected to autumn, also known as fall.

• Direct Rays: Sunlight strikes a surface directly.

• Indirect Rays: Sunlight strikes a surface at an angle.

Global Seasonality:

• Countries with winter at the same time as Portugal: USA and Japan
• Countries with winter at the same time as Australia: Brazil and South Africa
• Indonesia experiences very little change in seasons and equal hours of day and night all year.
• Countries with winter during June: South Africa and Australia

Diagrams

• In Diagram 1, it would be summer. In Diagram 2, it would be winter.

Daylight Hours Graph Interpretation:

• The graph represents a location in the Southern Hemisphere.
• The city represented is near the South Pole.
• The autumnal Equinox occurs in March.
• The temperature graph represents a location in the Southern Hemisphere.
• Winter Solstice occurs in June in displayed graph.

Solar Ray Diagrams:

• The seasons represent (northern/ southern) hemisphere.
• Position A receives direct sunlight at the Tropic of Cancer.
• Position B receives direct sunlight at the Equator.
• Position C receives direct sunlight at the Tropic of Capricorn.
• Position D receives direct sunlight at the Equator.