Astronomy 1
Review
1. A star starts off as a cloud of gases
and dust known as a
• Nebula
2. Gravity causes the nebula to collapse
and form a
• Protostar
3. Identify the process that produces light
and heat in a star?
• Fusion
4. Explain what occurs in this process.
• Hydrogen combines to produce helium and
light and heat.
5. What is the universe made of?
• matter and space
6. How does a star begin its life
cycle?
• As a nebula
7. What type of star is the sun
known as?
• Main sequence
8. A small, hot star is known as a
• White dwarf
9. A super giant may explode to form either a
neutron star or a black hole. This explosion is
called a
• Supernova
10. Identify the name of the
galaxy that our solar system
belongs to.
• Milky Way
11. Which star is closest to
Earth?
• The sun
12. Use the HR Diagram to answer the following questions.
B. Is the surface
temperature of white dwarf
stars higher or lower than
red super giants?
• Higher
• White dwarfs have a
temp of about 20,000 K
while super giants have
a temperature of about
3500K.
A. Most of the stars on the HR
Diagram are classified as which type
of star?
C. Describe the general
trend between temperature
and brightness for main
sequence stars.
• Main sequence stars
• As temperature
decreases, brightness
(luminosity) decreases.
13. Use the HR Diagram to answer the following questions.
B. The Herztsprung-Russell
diagram classifies stars by
their surface temperature
and luminosity. If a star has
a low surface temperature
and is considered very dim,
what type of star would it
probably be?
• Main sequence
A. What type of star has a low
temperature but a high luminosity?
• Red supergiants
• Temp = 2500 K
• Lum = 106
C. What type of star has a
high temperature and a
low luminosity?
• White dwarfs
• Temp =
30,000K
• Lum = 10-4
14. Use the HR Diagram to answer the following questions.
A. What is the
approximate surface
temperature of the
sun?
• 4800K
B. List the color of the
stars from hottest to
coldest:
• Blue, white,
yellow, red
BLUE
WHITE
YELLOW
RED
C. Would the surface
temperature of white
dwarf stars be higher or
lower than red giants?
• Higher
15. Label the diagram of the sun below.
B
A
A. Corona
B. Photosphere
D
C
C . Chromosphere
D. Core
16. Identify the part of the sun being
described:
a. Outer layer
• Corona
b. Carries out fusion (produces light & heat)
• Core
c. Gives off a red glow
• Chromosphere
d. gives off light
• photosphere
17. Explain the difference between sunspots
and prominences.
• Sunspots are dark, cooler areas of the
sun. Prominences are streams of flaming
gas.
18. Eruption of charged particles that can
interfere with communication if it reaches the
Earth.
• Solar flare
19. How do we calculate the amount of energy
produced by the sun?
• E = mc2
20. Which model of the solar system
describes our solar system? Explain why.
• Heliocentric model
• The sun is at the center of the solar
system and the planets revolve around it.
21. What was the first model called, that was
proven incorrect? How did it explain the solar
system?
• Geocentric model
• It described the Earth being at the center of
the solar system and the sun and the rest of
the plants revolving around it.
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23. Identify the planet being described:
a. Living things found on this planet
•Earth
b. Tilted on its side
•Uranus
c. Has the most rings around it
•Saturn
d. Earth’s twin
•Venus
e. Is reddish in color because of iron
•Mars
f. Has an atmosphere that mostly consists of carbon dioxide
and is very hot.
•Venus
24. What is Pluto classified as?
•A dwarf planet
25. What is revolution?
•The motion of one object around another object
26. Identify an object that carries out this process.
•The planets revolve around the sun.
•The moon revolves around the Earth.
•Asteroids and comets revolve around the sun.
27. Identify the smallest planet. Is it an outer or
inner planet?
•Mercury – inner planet
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29. Identify the largest planet. Is it an outer or inner planet?
•Jupiter – outer planet
30. Which planet is surrounded by rings? What are these rings
made of?
•Saturn – rocks and ice
31. How is a comet different from an asteroid?
•A comet is made of rock, dust and ice, while an asteroid
is a large chunk or rock. Both orbit the sun.
32. Explain what a shooting star really is.
•A meteor (rocky object that enters the atmosphere) that
burns up
33. What is a light year?
•Distance light travels in one year
34. Explain why we cannot describe Earth
as perfectly round.
•Its an oblate sphere. Flattened at the
poles and bulges out at the sides.
35. What is the shape of Earth’s orbit?
•Its an ellipse (oval/flattened circle)
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38. When is the Earth at aphelion?
•July – when it’s closest to the sun
39. When is the Earth’s orbital velocity
the greatest?
•January – at perihelion – when Earth is
closest to the sun
40. Describe Earth’s path if gravity did
not exist between the sun and the earth.
•It would travel in a straight line.
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The larger the mass, the
greater the gravity.
Mercury, Mars, Pluto
42. Explain the difference between
rotation and revolution.
• When an object rotates, it spins.
When an object revolves, it moves
around another object.
43. How long does it take the Earth to
complete 1 rotation?
• 24 hours/1 day
44. In which direction does Earth rotate?
• West to East
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365.25 days/1 year
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47. Explain when solar noon occurs.
• When sun is at its highest point in the
sky.
48. How long dies it take the Earth to revolve
around the sun?
• 365.25 days/1 year
49. Explain the time it takes a planet to
revolve around the sun as the distance
between the sun and a planet increases.
• The farther away a planet is from the
sun, the longer it takes to revolve around
the sun.
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51
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53
54
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Rotation of Earth’s on it’s axis.
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63. The Earth’s orbit around the sun is
represented in the diagram below.
D
A
C
B
A. Which letter represents the
Earth in perihelion?
A
B. Which letter represents the
Earth in aphelion?
B
C. At which letter does Earth
have the greatest orbital
velocity? Why?
A – its closer to the sun
D. At which letter is there less
gravity between the Earth and
the Sun? Why?
B – its farther from the
sun
63. The Earth’s orbit around the sun is
represented in the diagram below.
D
A
C
B
E. How many degrees is the
Earth tilted on its angle?
23.5
F. How long does it take the
Earth to travel from Point A,
back to Point A?
1 year/365.25 days