Module Introduction

This module introduces you to our solar system and how astronomers believe it formed, based on what we see around us and around other star systems in formation. We will also look at the discovery of other planets around other stars–called exoplanets.


Upon completion of this module, the student will be able to

  • Explain the nebular theory of the solar system formation
  • Describe the evidence which supports the nebular theory
  • List the IAU’s criteria to be a planet, and how this changed the status of Pluto
  • Explain what an exoplanet is, as well as the history of their discoveries
  • List examples of unusual stellar systems
  • Explain brown dwarfs and how they differ from stars and planets
  • Discuss stellar system habitable zones and what that has to do with life