The Earth in Space

THE EARTH IN SPACE

THE SEASONS

The Seasons

http://esminfo.prenhall.com/science/geoanimations/animations/01_EarthSun_E2.html

Earth at winter

Earth at fall

Earth at Spring

Earth at Summer

• The cause of the seasons on Earth

Please note: the North Pole always points toward the North Star (Polaris)

• Causes of seasons on a Earth

1. The tilt of Earth’s (or any planet’s) axis

2. Place or position of the Earth (or any planet) as it orbits around the Sun

• The effects of the 23.5° tilt on Earth

• The tilt of the Earth’s axis and the position of Earth in its orbit affect the angle that the sunlight strikes the Earth

Please draw this diagram

• The effects of the 23.5° tilt

• The tilt of the Earth’s axis and the position of Earth in its orbit affect the angle that the sunlight strikes the Earth

Please draw this diagram

• SolsticeSummer Solstice - the first day of

Summer* Northern Hemisphere June 21 or 22* Southern Hemisphere December 21 or 22

Winter Solstice - the first day of winter* Northern hemisphere December 21 or 22* Southern Hemisphere June 21 or 22

Position of N. Hemisphere at Summer Solstice

Position of S. Hemisphere atWinter Solstice

• Equinox • Equinox : a nearly equal number of daylight and dark hours

• Vernal Equinox the nearly equal number of daylight and nighttime hours when the Earth is positioned in its orbit exactly half way between summer and winter

• Atumnual Equinox the nearly equal number of daylight and nighttime hours when the Earth is positioned in its orbit exactly half way between summer and winter

http://www.teachersdomain.org/resource/psu10phy.sci.seasons/

Review1. What is rotation and how does it affect Earth2. What is revolution and how does it affect Earth3. Be able to compare and contrast rotation and

revolution4. What causes the seasons and why distance is not used

to determine the seasons5. Explain why seasons are opposite between the

Northern and Southern Hemisphere6. Understand the terms Solstice and Equinox7. Explain why and how the Tropics are determined8. Explain how the Arctic and Antarctic circles are

determined