8  Summary of Week 2

This week you have learned about the terrestrial planets Mercury, Venus, Earth and Mars, the gas giant planets Jupiter and Saturn, and the ice giants Uranus and Neptune. You’ve gained an appreciation for how vast everything is within the Solar System, and discovered ways of simplifying things by expressing mass and radius in terms of the sizes of Earth and Jupiter. You’ve also learned about the concepts of mass, volume and density, and how to calculate values of these using appropriate units.

You should now be able to:

• describe what is meant by a terrestrial planet and a giant planet, and the differences between these two planet types
• understand the scale of the Solar System and use the astronomical unit to measure it
• classify the planets Jupiter, Saturn, Uranus and Neptune as gas giants or ice giants
• describe what is meant by mass, radius, volume and density, and how these terms are used within astronomy
• understand the meaning of the symbols AU, M_J, R_J, M_E, R_E, M_⊕, R_⊕,, M_Sun,, R_Sun, M_⊙, R_⊙.

Next week you will start looking at planets outside the Solar System.

You can now go to Week 3.