Understanding humans' place in the universe has been an ongoing quest for scientists. Astronomy is the study of the Earth and all of the material in the universe. Astronomers search out answers about the mysteries of the unknown.

You are already an astronomer in a very simple sense. Each day, you are affected by the movement of the Earth causing day and night. If you have ever asked, “What is the reason for day and night?” you are acting like an astronomer. If you have ever wondered what causes the seasons, you are acting like an astronomer. You may wonder, why there are 365 days in our calendar year. Once again, you are acting like an astronomer.  The night sky is a source of wonder. The companion to the Earth, the Moon, also influences your life, even though you may not realize it yet. Although you may not know the patterns, you have observed the celestial bodies above such as stars, planets, comets, and nebula. That is what astronomers do, and that is what makes you a sort of astronomer, too. 

Getting Started

Before you begin your own journey through the study of the Universe, check to see if you already know some astronomy terms and concepts by completing this interactivity. Read each definition, and drag and drop the correct term into the blank provided. Then, click SUBMIT to check your response. Click the player to begin.

 

Key Vocabulary

To view the definitions for these key vocabulary terms, visit the course glossary.

anteumbra	galaxy	planet	summer solstice
aphelion	hypothesis	precession	synchronous rotation
astronomical unit	independent variable	problem	tilt
autumnal equinox	light-year	procedure	umbra
celestial sphere	lunar eclipse	revolution	universe
constants	Milky Way Galaxy	rotation	vernal equinox
control	nadir	qualitative date	waning
data	observation	quantitative data	waxing
dependent variable	parsec	scientific notation	winter solstice
eclipse	penumbra	solar eclipse	zenith
experiment	perihelion	Solar System
field of view	phase	star