CN – Earth’s Motion pg. 46-47

The Sun Nearest star to Earth Has a diameter 100 times greater than Earth’s Core reaches temperatures over 15,000,000℃ Surface reaches temps of 5,500℃

Earth’s orbit The Earth orbits around the Sun One complete revolution every 365.24 days due to the Sun’s gravitational pull As Earth orbits around the Sun, it rotates (spins on its rotational axis) One complete rotation every 24 hours

Earth’s Orbit Earth’s orbit is an ellipse (an elongated closed curve) The Sun is not centered in the ellipse causing the distance between the Sun and the Earth to be different depending on the time of the year.

Shape and Tilt of Earth Earth’s surface is curved, meaning that different parts of the Earth’s surface receive different amounts of the Sun’s energy Earth is tilted 23.5 degrees off center

Reason for the Seasons The tilt of the Earth, combined with Earth’s motion around the sun causes the seasons to change. The hemisphere tilted toward the Sun receives more daylight hours than the hemisphere tilted away from the Sun. THIS IS SUMMER! The hemisphere tilted away from the Sun receives less hours than the hemisphere tilted toward the Sun. THIS IS WINTER!

Reason for the Seasons

Solstice 2 times where Earth is EXTREMELY TILTED. June (summer) solstice is June 20/21 in the Northern Hemisphere December (winter) solstice is Dec 21/22 in the Northern Hemisphere

Equinox 2 times where Earth’s rotation axis is not tilted! March (spring) equinox is March 20/21 September (fall) equinox is Sept 22/23