658 – 665

Section 1

*Chapter 19: Earth Moon and Space

*Earth in Space

*What is Astronomy?

*Definition: Study of the moon, stars and space

*Why would it be beneficial to study Astronomy?

*Develop a calendar

*Agriculture

*Navigation

*Earth’s Movement

*Two Major ways Earth moves through space

*Rotation

*Revolution

*Earth’s Rotation

*Spinning of Earth upon its Axis

*Axis is line from North Pole to South pole

*Earth rotates Eastward

*Rotation causes 2 things: ?

*Rotation takes 24 hours = 1 Day

*Rotation

*Revolution

*Motion of Earth around Sun

*Earths path known as an ORBIT

*Orbit is Elliptical

*One complete revolution makes a ?

*Revolution

*Seasons on Earth

*We have four seasons: Winter, Spring, Summer and Fall

*The tropics and polar regions don’t. Why?

*Why is it warmer at the tropics than the poles?

*Earth’s Axis

*Why do we have seasons?

*Earth is tilted at 23.5 degrees

*We have seasons due to Earths tilt

*Not based upon distance from sun.

*Perihelion = Winter Solstice December 21

*Earth’s closest distance to the sun. 147.1 million Km

*Aphelion = Summer Solstice June 21

*Earth’s farthest distance from sun. 152.1 million Km

*Seasons

*Solstice and Equinox

*Solstice – Day of the year when the sun is at the farthest point north or south of the equator

*2 x’s a year

*Longest day and shortest day

*Equinox = equal sun coverage, equal day and night.

*2 x’s a year

*March 20 (spring) and September 22 (Fall/Autumn)