1. STANDARD 4a
Students know galaxies are clusters of billions of stars and may have different shapes

2. GALAXIES Spiral Galaxy
Spiral arms contain gas, dust, and many bright, young stars
Older stars are found in the bulge in the center of the galaxy

3. GALAXIES
The Milky Way, our home galaxy, is a spiral galaxy

4. GALAXIES
Barred Spiral Galaxy

5. GALAXIES Elliptical Galaxy Round shaped No spiral arms
Relatively little gas and dust
Contains mostly older stars

6. GALAXIES Irregular Galaxy No regular shape
Contains a great amount of gas, dust and young stars

7. GALAXIES 146. The Milky Way is an example of A an elliptical galaxy
B an irregular galaxy
C a spiral galaxy
D a quasar
ANSWER: C

8. GALAXIES 147. A typical galaxy may have ________ of stars A hundreds
B thousands
C millions
D billions
ANSWER: D

9. GALAXIES
148. The galaxy pictured below would best be classified as a(n)
A barred galaxy
B spiral galaxy
C irregular galaxy
D elliptical galaxy
ANSWER: B

10. STANDARD 4b
Students know that the Sun is one of many stars in the milky Way galaxy and that stars may differ in size, temperature, and color

11. STARS Stars are the source of all light in the universe
Stars produce energy through nuclear fusion, the combining of hydrogen atoms to form helium
The sun is an average size star

12. STARS

13. STARS
Stars differ in many ways, including temperature, color, size, composition, and brightness
The color and temperature are related
Blue stars are hot and bright
Yellow stars are of average temperature and brightness
Red stars are the coolest and the least bright

14. STARS Other types of stars include:
a. Blue giants – Massive blue stars that are very bright and hot
b. Red giants – Massive red stars that are very bright but cool
c. White dwarfs – very small stars that are hot but very dim

15. STARS
Every star begins its life as part of a nebula, a cloud of dust and gas
Gravity pulls the dust and gas together to form a star at the center
When the star becomes dense enough, nuclear fusion begins and the star lights up

16. STARS Eventually the star’s fuel runs out, then
Medium stars expand to become red giants, then shrink to become white dwarfs
Massive stars explode in a super nova and then end up as either a neutron star or a black hole

17. STARS

18. STARS
Hertzsprung-Russell diagram is used to classify stars by surface temperature and brightness.
90% of stars spend of their lives as main-sequence stars and form the center diagonal on the H-R diagram

19. STARS 149. What color star has the highest surface temperature? A blue
B red
C white
D yellow
ANSWER: A

20. STARS
150. Why do stars and other large celestial objects have a spherical shape?
A All objects become spherical when they melt
B Atomic and molecular forces cause all objects to become spherical
C Gravity attracts matter within these objects toward a central point
D Multiple collisions cause these objects to become rounded
ANSWER: C

21. STARS 151. Every star begins its life as a A nebula B white dwarf
C black hole
D pulsar
ANSWER: A

22. STARS
152. What determines whether a star becomes a white dwarf or a supernova?
A its color
B its diameter
C its mass
D its temperature
ANSWER: C

23. STARS
153. According to the diagram, which of the following stars is the coolest and dimmest
A Zeta Eridani
B Procyon
C the sun
D Barnard’s Star
ANSWER: D

24. STARS 154. Which of these stars is a main sequence star? A the sun
B Sirius B
C North Star
D Aldebaran
ANSWER: A

25. STANDARD 4c
Students know how to use astronomical units and light years as measure of distance between the Sun, stars, and Earth

26. MEASUREMENT IN SPACE
Measure distances in the solar system by using the astronomical unit (AU).
It is the average distance between the Earth and the sun (93 million miles)

27. MEASUREMENT IN SPACE
The distances between stars is so vast that we measure these distances in light-years.
Light-year is the distance light travels in one year (9.5 x 1015 m), which is 9 trillion km or 6 trillion miles

28. MEASUREMENT IN SPACE
156. If an astronomer observes that an object in the solar system is twice as far from the sun as Earth is, how far would that object be from the sun in astronomical units?
A 1 AU
B 2 AU
C 3 AU
D 4 AU
ANSWER: B

29. MEASUREMENT IN SPACE 157. What is the approximate distance to Saturn?
A 1 AU
B 1 light-year
C 10 AU
D 100 million meters
ANSWER: C

30. MEASUREMENT IN SPACE
159. The Milky Way is about 100,000 light-years wide. To cross the Milky Way, light takes about
A 100 years
B 1,000 years
C 100,000 years
D 1,000,000 years
ANSWER: C

31. STANDARD 4d
Students know that stars are the source of light for all bright objects in outer space and that the Moon and planets shine by reflected sunlight, not by their own light

32. Stars: the source of all light in the UNIVERSE
STARLIGHT
Stars: the source of all light in the UNIVERSE
The moon and planets shine at night from reflected light, not from their own light. This light comes only from the sun or other stars.

33. STARLIGHT
Stars differ in brightness. A star’s brightness depends on size and temperature
Large stars are brighter than small stars and hot stars are brighter than cool stars
Absolute brightness is the brightness the star would have if it were at a standard distance from Earth
Apparent brightness is the star’s brightness as seen from Earth.

34. STARLIGHT
The moon’s phases are the different shapes of the moon as seen from Earth
The moon’s phases demonstrate that the moon reflects the sun’s light to Earth
The phases depend on how much of the sunlit side of the moon faces Earth
A new moon occurs when the moon moves between the sun and Earth. The sunlit side of the moon faces away from Earth
A full moon occurs when the entire sunlit side of the moon faces Earth

35. STARLIGHT

36. STARLIGHT
An eclipse is when an object in space comes between the sun and another object
A solar eclipse occurs when the moon moves directly between Earth and the sun, blocking sunlight from reaching parts of Earth’s surface. New moon
A lunar eclipse occurs when Earth is directly between the moon and the sun, blocking sunlight from reaching the moon. Full moon

37. STARLIGHT

38. STARLIGHT
160. What phase of the moon would someone on Earth see when the moon is at position D?
A new moon
B first quarter
C full moon
D third quarter
ANSWER: C

39. STARLIGHT
161. On a clear night, a student notices that a star in the constellation Orion is much brighter than the star next to it. What observation has the student made?
A the first star has a greater apparent brightness than the second star
B the first star is producing more light than the second star
C the first star has a greater absolute brightness than the second star
D the first star is farther along in its life cycle than the second star
ANSWER: A

40. STARLIGHT 162. What produces light in a star? A combustion
B fluorescent minerals
C nuclear fusion
D reflection of light from planets
ANSWER: C

41. STARLIGHT 163. For a solar eclipse to occur
A the sun must be directly between Earth and the moon
B the moon must be directly between Earth and the sun
C the moon must be directly behind the Earth
D Earth must be directly between the sun and the moon
ANSWER: B

42. STARLIGHT
164. Four of Jupiter’s satellites (moons) can be seen from Earth using a telescope. What makes these satellites visible?
A Light emitted by the satellites
B light emitted by Earth and reflected by the satellites
C light emitted by Jupiter and reflected by the satellites
D light emitted by the sun and reflected by the satellites
ANSWER: D

43. STANDARD 4e
Students know the appearance, general composition, relative position and size, and motion of objects in the solar system, including planets, planetary satellites, comets, and asteroids

44. SOLAR SYSTEM
The solar system includes the sun, the nine planets, and all of the other objects orbiting the sun.
Other objects in the solar system include satellites (moons), asteroids, meteors and comets

45. SOLAR SYSTEM
The solar system formed from a cloud of gas and dust, called a nebula, that collapsed due to gravity.

46. SOLAR SYSTEM
The inner planets (Mercury to Mars) are small, dense, and rocky. Also called terrestial planets
The outer planets (Jupiter to Neptune) are large, made mostly of gas, and do not have solid surfaces. Also called the gas giants.
Pluto is similar to the composition of the inner planets and is now considered a dwarf planet

47. SOLAR SYSTEM

48. Relative Size of planets in our Solar System

49. Astronomy My Very Energetic Mother Just Served Us Nine Pizzas
OBJECTS IN OUR SOLAR SYSTEM
My Very Energetic Mother Just Served Us Nine Pizzas
SUN
Asteroid Belt

50. SOLAR SYSTEM
Comets are small bodies of ice, rock and dust loosely packed together and revolve around the sun in large orbits.
Originate either in the Kuiper belt or the Oort Cloud. These are regions that extend outside the orbit of Neptune

51. SOLAR SYSTEM
Asteroids are small, rocky bodies in orbit around the sun and are located between the orbits of Mars and Jupiter.
Astronomers believe that asteroids are leftover pieces of the early solar system that never came together to form a planet

52. SOLAR SYSTEM
Meteoroid is a small, rocky body that travels through space, usually created when comets or asteroids break up into smaller chunks
Meteor is a bright streak of light that results when a meteoroid burns up in Earth’s atmosphere
Meteorite is a meteoroid that reaches Earth’s surface without burning up completely

53. SOLAR SYSTEM 165. You can see the planets at night because
A they produce their own light
B sunlight reflects from their surfaces
C nuclear fusion takes place in their cores
D their surfaces are brighter than those of the stars
ANSWER: B

54. SOLAR SYSTEM 166. Which is the largest planet in the solar system?
A Venus
B Jupiter
C Saturn
D Neptune
ANSWER: B

55. SOLAR SYSTEM
167. What are the four planets closest to the sun called together?
A outer planets
B terrestrial planets
C solar system
D gas giants
ANSWER: B

56. SOLAR SYSTEM
168. Which planet has polar ice caps containing frozen water and carbon dioxide?
A Venus
B Jupiter
C Mars
D Neptune
ANSWER: C

57. SOLAR SYSTEM
169. Which is not a characteristic of all of the gas giants?
A surrounded by rings
B many moons
C composed mainly of hydrogen and helium
D rocky surfaces
ANSWER: D

58. SOLAR SYSTEM
171. Which object comes close to the Sun but is also found far from the Sun in a highly elliptical orbit?
A planet
B asteroid
C comet
D meteoroid
ANSWER: C

59. SOLAR SYSTEM
172. One complete revolution of Earth around the sun takes about
A one rotation
B one season
C one year
D one eclipse
ANSWER: C

60. SOLAR SYSTEM 173. 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
ANSWER: B