Download First Day Vocabulary

Name ____________________________
Date ____________
Period ______
Cosmology Vocabulary
Write your personal definition to the words listed below.
1. Scientific Method—approach to investigation; includes observation, theory and
testing
2. Theory—explains a set of observations and predicts what will happen; can be
changed if there is new evidence
3. Cosmology—study of the structure and evolution of the entire universe including
space, time, matter, and energy
4. Astronomy—branch of science dedicated to the study of everything in the
universe that lies above Earth’s atmosphere
5. Solar System—the sun and all the bodies that orbit it
6. Celestial Sphere—imaginary sphere surrounding Earth to which all objects in the
sky were once considered to be attached
7. Star—a glowing ball of gas held together by its own gravity and powered by
nuclear fusion in its core
8. Galaxy—gravitationally bound collection of stars
9. Galaxy Cluster—collection of galaxies held together by gravity
10. Universe—the totality of all space, time, matter and energy
11. Light Year—the distance that light travels in 1 year; 10 trillion km
12. Geocentric—Earth is the center of the solar system
13. Heliocentric—the Sun is the center of the solar system
14. Big Bang Theory—Event that cosmologists consider the beginning of the
universe