Astronomy Questions 1 - 3

Question 1 Geocentric Model – Earth is the center of the universe with all space bodies revolving around the Earth.

Question 1 Heliocentric Model – Sun is the center of the universe with all space bodies revolving around the Sun. Modern Heliocentric Model – Sun is the center of the Solar System

Question 2 The Sun revolves around the Earth every 24 hours.

Question 2 The Sun revolves around the Earth every 24 hours. The Moon revolves around the Earth approximately every 25 hours. All stars revolve around the Earth every 24 hours.

Question 2 The Sun revolves around the Earth every 24 hours. The Moon revolves around the Earth approximately every 25 hours. All stars revolve around the Earth every 24 hours. All planets revolve around the Earth. You can’t feel the Earth rotate or revolve. If Earth rotated, you would feel 1000 mph wind. Earth is the largest/most massive object in space; therefore everything revolves around it.

Question 3 Prove the Earth is moving - North Star

Question 3 Prove the Sun is in the center - Retrograde Motion North Star – If the North Star stays still while other stars revolve in the sky, it might mean the Earth is spinning and that the Earth’s northern axis is pointing to the North Star Prove the Sun is in the center - Retrograde Motion

Question 3 Demonstrate Retrograde Motion Retrograde Motion – a periodic backward movement or westward loop made by a planet as seen by Earth when moving in the sky http://alpha.lasalle.edu/~smithsc/Astronomy/images/mars.mov

Question 3 Retrograde Activity

Question 3 Explanation of Retrograde Motion – when Earth lines up with a planet and passes that planet because of its inner orbit, the planet will appear to move backwards (westward) in the Earth’s sky. http://www.mhhe.com/physsci/astronomy/applets/Retro/frame.html