1. Models of the Solar System

2. The observations that you have been making of the Sun, Moon and stars were the same observations made by early scientists. In order to understand the world we live in these scientists came up with models to explain the patterns they saw.

3. Aristotle earliest model easiest to imagine Universe was a gigantic sphere with the Earth at the center. On this sphere was attached the Sun, Moon and planets. Geocentric Model (Earth -Centered Model)

4. The observations that you have been making of the Sun, Moon and stars were the same observations made by early scientists. In order to understand the world we live in these scientists came up with models to explain the patterns they saw. Aristotle earliest model easiest to imagine Universe was a gigantic sphere with the Earth at the center. On this sphere was attached the Sun, Moon and planets. Geocentric Model (Earth -Centered Model) This model was accepted by scientists even though it could not explain the retrograde motion of Mars, Jupiter and Saturn.

5. Nicholas Copernicus early 1500s Sun was at the center of the model and the planets rotated around the Sun on the same solar plane Heliocentric Model. (Sun-Centered Model)

6. Nicholas Copernicus early 1500s Sun was at the center of the model and the planets rotated around the Sun on the same solar plane Heliocentric Model. (Sun-Centered Model)

7. Nicholas Copernicus early 1500s Sun was at the center of the model and the planets rotated around the Sun on the same solar plane Heliocentric Model. (Sun-Centered Model) Galileo used a telescope and provided evidence that supported the Heliocentric Model Galileo saw the Moon's surface, rings of Saturn, four moons of Jupiter and noted that Venus showed phases like the Moon This model had some problems predicting planetary motions.

8. Kepler Used math and deduced that the orbits were not circles but ellipses. (football shaped) Along with Sir Isaac Newton's Law of Gravitation predictions of planetary motion were more successful.

9. Kepler Used math and deduced that the orbits were not circles but ellipses. (football shaped) Along with Sir Isaac Newton's Law of Gravitation predictions of planetary motion were more successful.

10. Kepler Used math and deduced that the orbits were not circles but ellipses. (football shaped) Along with Sir Isaac Newton's Law of Gravitation predictions of planetary motion were more successful. In 1781, using the Sun-Centered model and Newton's Laws astronomers predicted the position and orbit of another planet and found Neptune.