THE EARTH IN SPACE THE SEASONS The Earth in Space

The Seasons Earth at winter Earth at Spring Earth at fall Earth at Summer http://esminfo.prenhall.com/science/geoanimations/animations/01_EarthSun_E2.html

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

Position of N. Hemisphere Solstice Summer 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 at Winter 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/

Review What is rotation and how does it affect Earth What is revolution and how does it affect Earth Be able to compare and contrast rotation and revolution What causes the seasons and why distance is not used to determine the seasons Explain why seasons are opposite between the Northern and Southern Hemisphere Understand the terms Solstice and Equinox Explain why and how the Tropics are determined Explain how the Arctic and Antarctic circles are determined