Name:_______________________________________________Date:________ Pd:______
Historical Models of Solar System
Heliocentric Theory
(“HELIO” CENTRIC)
Geocentric Theory (“GEO”
CENTRIC)
Meaning of
the Prefix
Definition
Astronomer
Who
Proposed the
Theory
DIAGRAM
1. _____________________________ is the study of the universe. A scientist who studies the universe is
called an _____________________________.
2. ___________________________ is the distance that light travels in one year; about 9.46 trillion
kilometers. This unit is used to measure distance of objects in space.
Galaxies (pages 596-597)
Galaxies (Types of Galaxies)
A large group of stars, dust and gas are called____________________________________________. There are
many different types of galaxies. ________________________________________, the astronomer for who
the _____________ ______________ _______________is named, began to
classify__________________________, mostly by their shapes, in the 1920’s.
Spiral Galaxies
_______________________ galaxies have a bulge at the center and spiral arms. The spiral arms are made up
of ________, _____________, and __________________ that have formed in these denser regions of gas and
dust.
The Milky Way
Observing other galaxies and making measurements inside our galaxy, the __________________ ________, has led
astronomers to think that our solar system is in a ______________ galaxy.


We live in the __________________ ________ galaxy.
What is the shape of the Milky Way Galaxy? ____________________________
Diagram a Spiral Galaxy below (be sure to include
where our Solar system would be):
Formation of the Universe (pages 600-601)
Big Bang Theory (What is it? When was it developed? Where did the evidence come from to support the Big
Bang?)
__________________________________________________________________________________________________
__________________________________________________________________________________________________
__________________________________________________________________________________________________
_________________________________________________________________________________________________
Place the following in order from the Largest to the Smallest: Earth, Sun, Moon, Milky Way Galaxy,
Universe, Solar System.
Largest
1.
Smallest
2.
3.
4.
5.
6.