1. Planet Review Watch the video clip. 1.Write down at least 5 facts that you did not know. 2.Write down one quiz question. (I will ask for these at a later date.) http://richannel.org/the-solar-system

2. Answers to Questions on Planet Chart 1.All of the heavy elements are born in a supernova.

3. Answers to Questions on Planet Chart 2. All of the planetesimals started spinning in the same direction when the nebula was a spinning disk. They continue to orbit around the sun in the same direction due to gravity and inertia.

4. Answers to Questions on Planet Chart 3. There is little/no gas on the inner planets due to: a.Too close to the sun and the amount of heat causes the lighter elements to “burn off.” b.The mass of the inner planets is much less than the outer planets and the gravitational force is too weak to hold on the lighter elements like Hydrogen and Helium.

5. Vocabulary Gravity – force of attraction between two objects Inertia – the tendency of an object at rest to stay at rest or to keep moving in the same direction at the same speed, until acted upon by an outside force

6. The retrograde motion of Mars in 2005. A composite image created by superimposing images taken on 35 different dates, each separated from the next by about a week. Retrograde Motion

7. Retrograde Motion - the apparent (not actual) backward motion of a planet http://astro.unl.edu/classaction/animations/r enaissance/retrograde.html http://astro.unl.edu/classaction/animations/r enaissance/retrograde.html Vocabulary

8. Ancient reasons for studying the skies Remember Science is Tentative yet Reliable.

9. History of Astronomy Aristotle – 2000 years ago believed in a geocentric model

10. History of Astronomy Copernicus – 1500 AD believed in a heliocentric model

11. Vocabulary Geocentric model – Earth-centered solar system Heliocentric model – Sun-centered solar system

12. History of Astronomy Galileo Galilei – 1600 AD 1 st scientist to use a telescope to view the stars Saw 4 moons orbit Jupiter (confirmed Copernicus)

13. Tycho Brahe – in late 1500’s he carefully observed and charted the positions of the planets for 20 years History of Astronomy Kepler – in the early 1600’s he worked for Brahe and used his observations to develop his 3 laws of planetary motion

14. Kepler’s 3 Laws of Planetary Motions http://youtu.be/XFqM0lreJYw http://www.teachersdomain.org/asset/npls12_v id_keplerorbits/ History of Astronomy