Module 3: Astronomy - The Universe
Understanding humans' place in the universe has been an ongoing quest of astronomers. Astronomy is the study of the Earth and all of the material in the universe. Astronomers search out evidence to answer the mysteries of the unknown. Astronomers ask questions about how the universe first formed, how it will end, how it is organized, and the objects within it. These huge questions of space and time can be overwhelming to think about.
You are already an astronomer in a very simple sense. If you have ever asked, "How did the universe begin?," you were acting like an astronomer. When you wonder about the stars, galaxies, black holes, and the fate of the universe, you are acting like an astronomer.
In this module, you will explore what astronomers have already discovered about these big questions. There is still much to learn, but astronomers already know a lot about the origins of the universe, galaxies, and stars. You will learn about some of the earliest astronomers and find out some of the most important discoveries of modern astronomy.
Getting Started
Before you begin your own journey through the study of the universe, check to see if you already know some terms and concepts related to astronomy by playing this interactive game. In this game, answer challenge questions to try and move your rocket across space. Click the player button to get started.
Key Vocabulary
To view the definitions for these key vocabulary terms, visit the course glossary.
| absolute magnitude | Galileo | Plato |
| Aristotle | globular cluster | poor cluster |
| Armstrong, Neil | Hertzsprung-Russell Diagram | protostar |
| Big Bang Theory | Hubble, Edwin | Ptolemy |
| binary star | Hubble Space Telescope | radio telescopes |
| black dwarf | Hubble's Law | red giant |
| black hole | irregular galaxy | redshift |
| blueshift | Kepler, Johannes | reflecting telescope |
| Brahe, Tycho | luminosity | rich cluster |
| closed universe | main sequence star | Shepard, Alan |
| Columbia | Milky Way Galaxy | singularity |
| constellation | National Aeronautics and Space Administration (NASA) | space telescope |
| Copernicus, Nicolas | nebula | spectral class |
| cosmic microwave background radiation | neutron star | spectroscope |
| cosmology | Newton, Sir Isaac | spiral galaxy |
| Doppler effect | nuclear fusion | Sputnik I |
| electromagnetic spectrum | observatory | star |
| ellipse | open cluster | Steady State Theory |
| elliptical galaxy | open universe | supergiant |
| energy | optical telescope | supernova |
| flat universe | parallax | Voyager I and II |
| Gagarin, Yuri | planetarium | white dwarf |
| galaxy |