MOTION

ASTRONOMY• The study of objects in space, including the moon, stars, and planets.

• Solar system

• Composed of the sun and the planets which travel around the sun.

• Galaxy

• A large group of stars (and solar systems) in space.

PREVIEW OF TODAYS LESSON!!• http://www.youtube.com/watch?v=WLRA87TKXLM

EARTH’S MOVEMENTS• Earth spins like a top on an imaginary line called its Axis.

• Earth’s axis is tilted 23.5 degrees.

• The spinning of Earth is called rotation.

• Rotation causes day and night.

• It takes Earth 24 hours to complete one rotation.

• Earth also travels around the sun in an elliptical, or oval orbit.

• This is called a revolution.

• The movement of one object around another.

• The path the Earth follows is called its orbit.

• One revolution of Earth around the sun is 365.25 days.

SEASONS• The more direct sunlight an area of Earth experiences, the warmer it will be.

• Due to the tilt of her axis, different areas of Earth get direct sunlight at different times.

• When the Northern Hemisphere is tilted towards the sun, it receives more direct sunlight.

• Summer in the north, winter in the south.

• When the southern Hemisphere is tilted towards the sun, it receives more direct sunlight.

• Summer in the south, winter in the north.

• Summer solstice

• When the sun’s light reaches its farthest distance North of the equator.

• June 21st

• Winter Solstice

• When the sun’s light reaches its farthest point south of the equator.

• December 21st

• Spring and Fall Equinoxes

• Occurs when neither hemisphere is pointed directly at the sun (in-between the winter and summer solstices).

• Vernal Equinox-March 21st.

• Autumnal Equinox-September 22nd.