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1. _____began from a nebula that was
disturbed (big bang)
2. _____observed the phases of
Venus (astronomers)
3. _____theory of the sun centered
view of the solar system
(astronomers)
4. _____causes day and night, winds
and currents to curve (rotation and
revolution)
5. _____ changing wind direction
keeps what going
1.
2.
3.
4.
5.
6.
What is a light year?
What is a galaxy?
What are the three types of galaxies?
What is the name of the galaxy our solar system is
located in?
What type of galaxy is the Milky Way?
Where is our solar sytem located in the Milky
Way?
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1. A light year is the distance light travels in a
year. 1light year=9.5 trillion kilometers
2. A galaxy is a large group of stars in space.
3. The three types of galaxies are spiral,
elliptical (oval), and irregular.
4. The Milky Way Galaxy
5. It is a barred spiral galaxy with a bulge in
the middle (cooler yellow stars) and spiral
arms that spin out (made of hot blue stars)
6. Our solar system is located on an outer arm
called the Orion arm.
Milky Way Galaxy = Spiral Galaxy
The Milky Way Galaxy
1. Number of Stars-200-400
billion
2. Diameter-100,000 light years
3. Thickness-1,000 to 3,000 light
years
4. All objects revolve around
center of the galaxy
The Milky Way Galaxy
• 5. Location of our solar system-outer
arm
• 6. Distance from the sun to the center
of the galaxy-30,000 light years
• 7. Galactic Year (period of revolution of
our solar system) -240 million years
Local Stellar Cluster = A local group of
stars that includes our Sun.
Local Cluster of Galaxies