2. Earth’s Motion Around the Sun
• The Moon orbits the Earth, but at the
same time, the Earth-Moon system orbits
the Sun.
11.2 The Sun-Earth-Moon System
3. Earth’s Orbit
• The path of Earth’s orbit is an ellipse.
• Earth is closest to the Sun in January.
• Earth is farthest from the Sun in July.
11.2 The Sun-Earth-Moon System
4. Earth’s Orbit Continued
• Earth is closest to the Sun in January.
• Earth is farthest from the Sun in July.
5. Earth’s Rotation
• Earth rotates on its axis once every 24 hours.
• The rotation causes day and night.
• Earth’s axis of rotation is 23.5° tilted to the
plane of orbit around the Sun.
11.2 The Sun-Earth-Moon System
6. The Moon—Earth’s Satellite
• Earth has one moon revolving around it.
• A satellite is an object that revolves
around a planet.
11.2 The Sun-Earth-Moon System
7. Formation of the Moon
• Scientists think that the Moon formed when
another large object collided with Earth.
• A large amount of matter was ejected into
space in the collision.
11.2 The Sun-Earth-Moon System
8. Formation of the Moon (cont.)
• The material eventually formed the Moon.
11.2 The Sun-Earth-Moon System
9. The Motion of the Moon
• Gravitational force between Earth and the
Moon causes the Moon to orbit the Earth.
• The Moon rotates on its axis once every
28 days.
11.2 The Sun-Earth-Moon System
10. The Motion of the Moon (cont.)
11.2 The Sun-Earth-Moon System
11. Phases of the Moon
• The Moon reflects sunlight.
• As the Moon travels around Earth, the
illuminated portion changes.
• The different appearances of the Moon are
called lunar phases.
11.2 The Sun-Earth-Moon System
12. Eclipses
• An eclipse is a total or partial blocking of a
star , planet, or moon by a different one.
11.2 The Sun-Earth-Moon System
• There are two types of eclipses:
– Lunar
– Solar
13. Lunar Eclipses
• A lunar eclipse occurs when a portion of the
Moon is shaded from direct sunlight by Earth.
• During a lunar eclipse, Earth moves between
the Sun and the Moon when the Moon is full.
11.2 The Sun-Earth-Moon System
14. Solar Eclipses
• For a total solar eclipse on Earth, there
must be perfect alignment of the Moon
and the Sun.
• The Moon casts a small shadow on Earth.
11.2 The Sun-Earth-Moon System
15. When is Earth farthest from the Sun?
A January
B April
C July
D October
11.2 The Sun-Earth-Moon System
16. What is the phase of the Moon called
when it is fully illuminated?
A new moon
B full moon
C blue moon
D harvest moon
11.2 The Sun-Earth-Moon System
17. The light from the moon is produced
by ____.
A the Moon itself
B Earth
C the Sun
D satellites
11.2 The Sun-Earth-Moon System
20. The Inner Planets
• The inner planets include Mercury, Venus,
Earth, and Mars.
• All are rocky in
composition.
• All are within
1.5 AUs of
the Sun.
11.3 The Planets and Their Moons
22. Mercury
• Mercury is the closest planet to the Sun.
• Mercury has a highly elliptical orbit and
travels faster than any other planet.
• Surface temperatures often reach 467°C.
11.3 The Planets and Their Moons
23. Venus
• Venus is the second planet from the Sun.
• Venus is similar to Earth in size, mass,
composition, and distance from the Sun.
• Venus is covered by thick clouds of
carbon dioxide.
• Venus is often the brightest object in the
sky except for the Moon.
11.3 The Planets and Their Moons
24. Earth
• Earth is the third planet from the Sun.
• Earth is the only body in our solar system
known to have life on it.
• Earth’s atmosphere affects the climate,
shields the surface from harmful radiation,
and burns up most meteoroids before
they strike the surface.
11.3 The Planets and Their Moons
25. Mars
• Mars is the fourth planet from the Sun.
• Mars has two small moons, Phobos
and Deimos.
• Mars may once have had flowing water.
11.3 The Planets and Their Moons
26. The Outer Planets
• The outer planets include Jupiter, Saturn,
Neptune, Uranus, and Pluto.
11.3 The Planets and Their Moons
27. Jupiter
• Jupiter is the largest planet in our
solar system.
• Jupiter’s composition of mostly hydrogen
and helium and resembles a small star.
• Jupiter is the first planet from the Sun to
have rings.
11.3 The Planets and Their Moons
28. Jupiter (cont.)
• Jupiter has more than 60 moons; the four
largest are Ganymede, Callisto, Io, and
Europa.
11.3 The Planets and Their Moons
29. Saturn
• Saturn is composed mostly of hydrogen and
helium.
• Saturn’s rings are composed mainly of ice
and rock.
• Saturn has over 30 known moons, the
largest is Titan.
11.3 The Planets and Their Moons
30. Uranus
• Uranus is a blue-green gas planet that
rotates on its side.
11.3 The Planets and Their Moons
31. Uranus (cont.)
• Uranus has 27 known moons and a series
of small rings.
• The atmosphere is mainly hydrogen and
helium.
11.3 The Planets and Their Moons
32. Neptune
• Neptune was the first planet located by
theoretical predictions rather than through
ordinary observations.
• Neptune has 13 known moons and several
rings.
• Neptune’s atmosphere is mostly hydrogen,
helium, and methane.
11.3 The Planets and Their Moons
33. Pluto
• Pluto is the smallest and most distant of
the planets.
• Pluto might be composed of a rocky core
surrounded by ice.
• Pluto takes 248 years to complete one
revolution around the Sun.
• Pluto has one moon, Charon, that is about
the same size as Pluto.
11.3 The Planets and Their Moons
34. Which of the following is NOT one of
the inner planets?
A Mars
B Jupiter
C Venus
D Earth
11.3 The Planets and Their Moons
35. Which planet is unique in the
position of its axis of rotation?
A Jupiter
B Saturn
C Mercury
D Uranus
11.3 The Planets and Their Moons
36. The outer planets are composed
mostly of ____.
A gases
B rocks
C glaciers
D dust
11.3 The Planets and Their Moons
39. Asteroids
• Asteroids are rocky objects, smaller than a
planet, found between the orbits of Mars
and Jupiter.
• There are
hundreds of
thousands of
asteroids in the
solar system.
11.4 Asteroids, Comets, and Meteoroids
40. Asteroids (cont.)
• Asteroids are thought to be leftover material
from the formation of the solar system.
11.4 Asteroids, Comets, and Meteoroids
41. Comets
• A comet is a small, icy body in orbit
around the Sun.
• Some comets have highly elliptical orbits
bringing them close to the Sun.
• The solid part of a comet is called the
nucleus and is made of icy material.
• The comet also contains dust, frozen
gases, and bits of rock.
11.4 Asteroids, Comets, and Meteoroids
42. Comets (cont.)
• When a comet passes near the Sun, the
gases are vaporized forming a tail.
11.4 Asteroids, Comets, and Meteoroids
43. Comets (cont.)
• Short-period comets take less than 200
years to orbit the Sun and are highly
predictable.
• Long-period comets
have orbits that take
more than 200 years
to complete.
11.4 Asteroids, Comets, and Meteoroids
44. A Tenth Planet?
• In 2005, scientists detected an object larger
than Pluto and gave it the temporary name
of 2003 UB313.
• Nicknamed Xena,
it is undecided
whether this
object is a planet
or not.
11.4 Asteroids, Comets, and Meteoroids
45. Meteoroids
• Meteoroids are solid, interplanetary particles
passing through Earth’s atmosphere.
• A meteor is the streak of light seen in the
sky produced by a meteorite.
• A meteorite is the remaining portion of the
meteoroid that reaches Earth’s surface.
11.4 Asteroids, Comets, and Meteoroids
46. Meteoroids (cont.)
• Most scientists think that meteoroids came
from planets that broke apart during the
formation of our solar system.
11.4 Asteroids, Comets, and Meteoroids
47. Impact Craters on Earth
• Most meteoroids burn up in the
atmosphere.
• Some large meteors produce impact
craters, such as the Barringer Crater in
Arizona.
11.4 Asteroids, Comets, and Meteoroids
48. A meteoroid that strikes the surface
of the Earth is called a(n) ____.
A asteroid
B meteor
C comet
D meteorite
11.4 Asteroids, Comets, and Meteoroids
49. What protects Earth from most
meteoroids?
A oceans
B the atmosphere
C the Moon
D Mars
11.4 Asteroids, Comets, and Meteoroids
50. Where are most of the asteroids in
the solar system found?
A between Jupiter and Saturn
B Saturn’s rings
C between Mars and Jupiter
D Kuiper Belt
11.4 Asteroids, Comets, and Meteoroids
51.
52. Chapter Assessment
California Standards Practice
Concepts in Motion
Image Bank
Science Online
Chapter Resources Menu
Click on a hyperlink to view the corresponding feature.
53. Which planet has the two moons,
Phobos and Deimos?
A Mercury
B Mars
C Jupiter
D Neptune
54. A lunar eclipse occurs when Earth is
in the Moon’s shadow.
A True
B False
55. What is the phase of the Moon called
when no part of it is illuminated?
A full moon
B black moon
C harvest moon
D new moon
56. How many planets in our solar
system are known to have had life?
A 1
B 2
C 3
D none of the above
57. Which of the following summarizes
Kepler’s third law of planetary motion?
A Planets spin faster as they get closer to
the Sun.
B The farther a planet is from the Sun, the
longer it takes to complete one orbit.
C Planets travel faster when they are
closer to the Sun.
D Planets travel in an elliptical orbit around
the Sun.
58. Who discovered the 4 largest moons
of Jupiter?
A Kepler
B Newton
C Copernicus
D Galileo
SCI 4.e
59. What is the closest outer planet to
the Sun?
A Mercury
B Jupiter
C Mars
D Saturn
SCI 4.e
60. Which of the following consists of a
frozen ball of rock?
A a comet
B an asteroid
C a meteor
D Mars
SCI 4.e
61. What is the third planet from
the Sun?
A Venus
B Mars
C Earth
D Titan
SCI 4.e
62. What force keeps the Earth orbiting
the Sun?
A the magnetic field of Earth
B the Moon’s gravity
C the Sun’s gravity
D the rotation of Earth on its axis
SCI 2.g