Relative Size of Planets and Stars Pre-reading handout and questions. Relative Size of Planets and Stars Presentation by: Thomas Castiglione This presentation has been adapted with permission from Geoffrey Rizzie

California Earth Science Standards 1. Astronomy and planetary exploration reveal the solar system’s structure, scale, and change over time. As a basis for understanding this concept: a. Students know how the differences and similarities among the sun, the terrestrial planets, and the gas planets may have been established during the formation of the solar system. d. Students know the evidence indicating that the planets are much closer to Earth than the stars are. 2. Earth-based and space-based astronomy reveal the structure, scale, and changes in stars, galaxies, and the universe over time. As a basis for understanding this concept: a. Students know the solar system is located in an outer edge of the disc-shaped Milky Way galaxy, which spans 100,000 light years. b. Students know galaxies are made of billions of stars and comprise most of the visible mass of the universe.

Questions to think about… What is a terrestrial planet? What is a gas giant? What is a star? How can space exploration help us with our understanding of Earth? Do you think that it is possible that there may be life elsewhere in the universe?

Why astronomy? Our ancestors have looked to the skies for answers to questions throughout the ages. Critical discoveries have been made that have lead to modern day farming, navigation, and understanding of heavenly motions. Today we look to space to gain a better understanding of Earth’s history, and look for new energy alternatives based on celestial energy.

Terrestrial Planets and Moons

Gas Giants compared to Terrestrial Planets

A Typical Star

Hubble Deep Field http://hubblesite.org/gallery/