1. Topic: The Inner Planets PSSA: 3.4.7.D/S8.D.3.1

2. Objective: TLW explain how distance is measured in our solar system. TLW compare the characteristics of the inner planets.

3. MI #1: Measuring Interplanetary Distance Scientists measure distances in our solar system using astronomical units (AU). 1 AU = the average distance between the Earth and the sun (roughly 150,000,000 km). Other methods (light minutes, miles, kilometers) may be used depending on the situation.

4. MI #2: Main Parts of the Solar System The solar system is divided into two main regions; the inner planets and the outer planets. The inner planets are also known as terrestrial planets because they are dense and rocky. The outer planets are gas giants

5. MI #3: Mercury Per. Of Rotation = 59 days Per. Of Revolution = 88 days There is no atmosphere, which results in a heavily cratered surface and extreme temp. difference from day to night (427°C during the day, -173°C at night) No moons

7. MI #4: Venus Per. of Rotation = 243 days Per. Of Revolution = 225 days Dense atmosphere with high concentration of CO 2 ; the green house effect creates an average surface temperature of 464°C. No moons

9. MI #5 Earth Per. Of Rotation = 24 hours (1 day) Per. Of Revolution = 365.25 days Earth has water in a liquid state and is the only planet known to support life. Earth has one moon (Luna – but we usually just call it “the moon”)

11. MI #6: Mars Per. Of Rotation = 24 hours, 37 minutes Per. Of Revolution = 687 days The “Red Planet” was once geologically active – it is the home to the largest volcano in the solar system (Olympus Mons); it also has polar ice caps. 2 moons – Phobos and Deimos

13. So What…? Real Life Application Understanding the inner planets is important to understanding the Earth’s relationship to other parts of the solar system.