Name: 
 

The Solar System



Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
 

1. 

The model in which Earth is at the center of the system of planets is called the
a.
solar system.
b.
heliocentric system.
c.
geocentric system.
d.
Copernican system.
 

2. 

Copernicus explained that
a.
the sun is at the center of the system of planets.
b.
the sun and the planets revolve around Earth.
c.
the geocentric system is correct.
d.
there are only six planets.
 

3. 

The heliocentric system gained support when Galileo observed that
a.
one side of the moon always faces Earth.
b.
most of the smaller planets are closer to the sun.
c.
Venus goes through phases similar to those of Earth's moon.
d.
the orbit of each planet is an ellipse.
 

4. 

The two factors that combine to keep the planets in orbit are
a.
gravity and orbital speed.
b.
orbital speed and mass.
c.
mass and inertia.
d.
gravity and inertia.
 

5. 

The tendency of a moving object to continue moving in a straight line or a stationary object to remain in place is called
a.
orbital speed.
b.
mass.
c.
inertia.
d.
gravity.
 

6. 

What do all of the inner planets have in common?
a.
They have the same period of revolution.
b.
They have the same period of rotation.
c.
They have the same diameter.
d.
They are small and have rocky surfaces.
 

7. 

Earth is unique among the planets because of
a.
its rocky surface.
b.
its oceans.
c.
its large size.
d.
the direction in which it rotates.
 

8. 

The atmospheres of the gas giant planets cannot escape into space because
a.
the gases are too heavy.
b.
the gases solidify at higher elevations.
c.
the planets have very strong gravity.
d.
although they are big, the planets have little mass.
 

9. 

What do the first four outer planets have in common?
a.
They are much larger than Earth and do not have solid surfaces.
b.
They are about the same size as Earth and do not have solid surfaces.
c.
They are much larger than Earth and are solid.
d.
They are about the same size as Earth and are solid.
 

10. 

Saturn's rings are made up mostly of
a.
nitrogen and helium.
b.
ice and water vapor.
c.
volcanic dust particles.
d.
chunks of ice and rock.
 

11. 

Uranus is different from most other planets because it
a.
is the farthest from the sun.
b.
is mostly nitrogen and helium.
c.
rotates on its side.
d.
has the most moons.
 

12. 

Pluto is different from the other outer planets because it
a.
is almost entirely made of gases.
b.
is much larger than the others.
c.
has the most moons.
d.
is small and has a solid surface.
 

13. 

What shape are the orbits of most comets?
a.
long, narrow ellipses
b.
circles
c.
nearly circular ellipses
d.
spherical
 

14. 

The asteroid belt is located
a.
between Earth and Mars.
b.
between Mars and Jupiter.
c.
between Jupiter and Saturn.
d.
between Saturn and Uranus.
 

15. 

Meteoroids usually come from
a.
debris from other planets.
b.
solar winds.
c.
beyond the solar system.
d.
comets or asteroids.
 

16. 

When a meteoroid enters Earth's atmosphere, it produces a streak of light called a
a.
meteor.
b.
asteroid.
c.
meteorite.
d.
comet.
 

17. 

Conditions required for life on Earth include
a.
alternating day and night cycles.
b.
extreme differences in elevation.
c.
polar ice caps.
d.
liquid water.
 

18. 

The hypothesis that Mars may once have had the conditions needed to support life is based on
a.
its similar size to Earth.
b.
its reddish surface.
c.
surface patterns that look like dried streambeds.
d.
the system of canals seen by Schiaparelli.
 

Completion
Complete each sentence or statement.
 

19. 

The force that pulls the moon toward Earth is called ____________________.
 

 

20. 

The planets that are closer to the sun than Earth are Venus and ____________________.
 

 

21. 

The only outer planet with a solid surface is ____________________.
 

 

22. 

The atmospheres of the gas giants are composed mainly of the element ____________________.
 

 

23. 

Few comets pass near Earth because their ____________________ are so elliptical.
 

 

Short Answer
 
 
solar_system_test_files/i0270000.jpg
 

24. 

Write the name of the planet that is labeled with each number.
1.
2.
3.
4.
 

25. 

What objects are found at 5? Why are they not considered to be planets?
 



 
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