1. Prentice Hall EARTH SCIENCE
Tarbuck Lutgens 

2. STARTER Using figure 3 on page 616 answer the following questions
What is the main difference between these two models of the solar system?
How do changing models of the solar system demonstrate the self-correcting nature of science?

3. 22.1 Early Astronomy Key Concepts Vocabulary
How does the geocentric model of the solar system differ from the heliocentric model?
What were the accomplishments of early astronomers?
Vocabulary
astronomy, geocentric, heliocentric, retrograde motion, ellipse, astronomical unit (AU)

4. 22.1 Early Astronomy Ancient Greeks
 Astronomy is the science that studies the universe. It includes the observation and interpretation of celestial bodies and phenomena.
 The Greeks used philosophical arguments to explain natural phenomena.
 The Greeks also used some observational data.

5. Astrolabe
Early astronomers often used instruments called astrolabes to track the positions on the sun and stars.
Makes no sense without caption in book

6. Calculating Earth’s Circumference
This diagram shows the orientation of the sun’s rays at Syene (Aswan) and Alexandria in Egypt on June 21 when Erastothenes calculted Earth’s circumfrence.
Makes no sense without caption in book

7. 22.1 Early Astronomy Ancient Greeks  Geocentric Model
• In the ancient Greeks’ geocentric model, the moon, sun, and the known planets—Mercury, Venus, Mars, and Jupiter—orbit Earth.
 Heliocentric Model
• In the heliocentric model, Earth and the other planets orbit the sun.

8. Geocentric and Heliocentric Models
Makes no sense without caption in book
A Geocentric Model of the Universe
A Heliocentric Model of the Universe

9. 22.1 Early Astronomy Ancient Greeks  Ptolemaic System
• Ptolemy created a model of the universe that accounted for the movement of the planets.
• Retrograde motion is the apparent westward motion of the planets with respect to the stars.

10. Retrograde Motion
Makes no sense without caption in book
When viewed from Earth, Mars moves eastward among the stars each day. Then periodically it appears to stop and reverse direction. This apparent movement, called retrograde motion occurs because Earth has a faster orbital speed than Mars and overtakes it.

11. Reading Checkpoint
What is retrograde motion??

12. 22.1 Early Astronomy The Birth of Modern Astronomy
 Nicolaus Copernicus
• Copernicus concluded that Earth is a planet. He proposed a model of the solar system with the sun at the center.

13. 22.1 Early Astronomy The Birth of Modern Astronomy  Tycho Brahe
• Tycho Brahe designed and built instruments to measure the locations of the heavenly bodies. Brahe’s observations, especially of Mars, were far more precise than any made previously.

14. 22.1 Early Astronomy The Birth of Modern Astronomy  Johannes Kepler
• Kepler discovered three laws of planetary motion:
1. Orbits of the planets are elliptical.
2. Planets revolve around the sun at varying speed.
3. There is a proportional relationship between a planet’s orbital period and its distance to the sun.

15. 22.1 Early Astronomy The Birth of Modern Astronomy  Johannes Kepler
• An ellipse is an oval-shaped path.
• An astronomical unit (AU) is the average distance between Earth and the sun; it is about 150 million kilometers.

16. Planet Revolution
A line connecting a planet to the sun would move in such a manner that equal areas are swept out in equal times. Thus, planets revolve slower when they are farther from the sun and faster when they are closer.
Makes no sense without caption in book

17. 22.1 Early Astronomy The Birth of Modern Astronomy  Galileo Galilei
• Galileo’s most important contributions were his descriptions of the behavior of moving objects.
• He developed his own telescope and made important discoveries:
1. Four satellites, or moons, orbit Jupiter.
2. Planets are circular disks, not just points of light.
3. Venus has phases just like the moon.
4. The moon’s surface is not smooth.
5. The sun has sunspots, or dark regions.

18. The Solar System Model Evolves
In the Ptolemaic
system, the orbit of
Venus lies between
the sun and Earth.
Makes no sense without caption in book
In the Copernicus
system, Venus orbits
the sun and all its
phases are visible
from Earth
As Galileo observed,
Venus goes through
phases similar to the
moon.

19. 22.1 Early Astronomy The Birth of Modern Astronomy  Sir Isaac Newton
• Although others had theorized the existence of gravitational force, Newton was the first to formulate and test the law of universal gravitation.
 Universal Gravitation
• Gravitational force decreases with distance.
• The greater the mass of an object, the greater is its gravitational force.

20. Gravity’s Influence on Orbits
Makes no sense without caption in book
Without the influence of gravity, planets would move in a
straight line out into space.

21. Review of 22.1
Create three review questions with answers from section 22.1.
Hold you paper up so I can come by and check off when you are finished.

22. Who am I?
I built instruments called pointers to measure the location of heavenly bodies. I came up with the most precise location of Mars than had ever been made.

23. Tycho Brahe

24. Who am I?
I was the first to formulate and test the Law of Universal Gravitation.

25. Sir Isaac Newton

26. Who am I?
I determined that Earth is a planet, not the center of the universe.

27. Copernicus

28. Who am I? I invented the telescope and made other discoveries such as:
Planets are circular disks
Venus has phases like the moon
The moon’s surface is not smooth
The are dark regions called sunspots

29. Galileo

30. Who am I?
I came up with the three laws of planetary motion.

31. Johannes Kepler

32. Who am I?
I came up with the concept of retrograde motion, which is the apparent westward drift of planets.

33. Ptolemy

34. Who am I?
I was credited for determining the circumference of Earth.

35. Eratosthenes

36. Who am I?
I determined that the Earth was round because it always cast a curved shadow when it passed between the sun and the moon.

37. Aristotle

38. A. built instruments called pointers to measure the location of heavenly bodies
B. Earth is a planet, not the center of the solar
system
C. credited for finding the circumference of the Earth
D. formulated and tested the Law of Universal Gravitation
E. concluded the Earth is round
F. retrograde motion
G. 3 laws of planetary motion
H. telescope, sunspots, planets are circular disks, discovered the moon’s surface is not smooth

39. 22.2 The Earth-Moon-Sun System
Key Concepts
In what ways does Earth move?
What causes the phases of the moon?
Why are eclipses relatively rare events?
Vocabulary
Rotation, revolution, precession, perihelion, aphelion, perigee, apogee, phases of the moon, solar eclipse, lunar eclipse

40. 22.2 The Earth–Moon–Sun System
Motions of Earth
22.2 The Earth–Moon–Sun System
 The two main motions of Earth are rotation and revolution. Precession is a third and very slow motion of Earth’s axis.

41. Stonehenge, an Ancient Observatory
Makes no sense without caption in book

42. 22.2 The Earth–Moon–Sun System
Motions of Earth
22.2 The Earth–Moon–Sun System
 Rotation
• Rotation is the turning, or spinning, of a body on its axis.
• Two measurements for rotation:
1. Mean solar day is the time interval from one noon to the next, about 24 hours.
2. Sidereal day is the time it takes for Earth to make one complete rotation (360º) with respect to a star other than the sun—23 hours, 56 minutes, 4 seconds.

43. Sidereal Day
Makes no sense without caption in book

44. 22.2 The Earth–Moon–Sun System
Motions of Earth
22.2 The Earth–Moon–Sun System
 Revolution
• Revolution is the motion of a body, such as a planet or moon, along a path around some point in space.
• Perihelion is the time in January when Earth is closest to the sun.
• Aphelion is the time in July when Earth is farthest from the sun.

45. 22.2 The Earth–Moon–Sun System
Motions of Earth
22.2 The Earth–Moon–Sun System
 Earth’s Axis and Seasons
• The plane of the ecliptic is an imaginary plane that connects Earth’s orbit with the celestial sphere.
• Because of the inclination of Earth’s axis to the plane of the ecliptic, Earth has its yearly cycle of seasons.
Spring Equinox- March 20 or 21
Autumn Equinox- September 22 or 23
Summer Solstice- June 21 or 22
Winter Solstice- December 21 or 22

46. The Ecliptic
Makes no sense without caption in book

47. 22.2 The Earth–Moon–Sun System
Motions of Earth
22.2 The Earth–Moon–Sun System
 Precession
• Precession traces out a cone over a period of 26,000 years.
 Earth–Sun Motion
• The solar system speeds in the direction of the star Vega.
• The sun revolves around the galaxy.
• Earth is presently approaching one of its nearest galactic neighbors, the Great Galaxy in Andromeda.

48. Precession
Makes no sense without caption in book

49. Reading Checkpoint
What is precession?

50. 22.2 The Earth–Moon–Sun System
Motions of the Earth–Moon System
22.2 The Earth–Moon–Sun System
 Perigee is the point at which the moon is closest to Earth.
 Apogee is the point at which the moon is farthest from Earth.

51. 22.2 The Earth–Moon–Sun System
Motions of the Earth–Moon System
22.2 The Earth–Moon–Sun System
 Phases of the Moon
• The phases of the moon are the progression of changes in the moon’s appearance during the month.
• Lunar phases are a result of the motion of the moon and the sunlight that is reflected from its surface.

52. Phases of the Moon
Makes no sense without caption in book

53. 22.2 The Earth–Moon–Sun System
Motions of the Earth–Moon System
22.2 The Earth–Moon–Sun System
 Lunar Motions
• The synodic month is based on the cycle of the moon’s phases. It lasts 29 1/2 days.
• The sidereal month is the true period of the moon’s revolution around Earth. It lasts 27 1/3 days.

54. 22.2 The Earth–Moon–Sun System
Motions of the Earth–Moon System
22.2 The Earth–Moon–Sun System
 Lunar Motions
• The difference of two days between the synodic and sidereal cycles is due to the Earth–moon system also moving in an orbit around the sun.
• The moon’s period of rotation about its axis and its revolution around Earth are the same, 27 1/3 days. It causes the same lunar hemisphere to always face Earth.

55. Lunar Motions
Makes no sense without caption in book

56. Reading Checkpoint
Why does the same side of the moon always face Earth?

57. 22.2 The Earth–Moon–Sun System
Eclipses
22.2 The Earth–Moon–Sun System
 Solar eclipses occur when the moon moves in a line directly between Earth and the sun, casting a shadow on Earth.
 Lunar eclipses occur when the moon passes through Earth’s shadow.
 During a new-moon or full-moon phase, the moon’s orbit must cross the plane of the ecliptic for an eclipse to take place.

58. Solar Eclipse
Makes no sense without caption in book

59. Lunar Eclipse
Makes no sense without caption in book

60. 22.3 Earth’s Moon Key Concepts Vocabulary
What processes create surface features on the moon?
How did the moon form?
Vocabulary
Crater, ray, mare, rille, lunar regolith

61. 22.3 Earth’s Moon The Lunar Surface  Craters
• A crater is the depression at the summit of a volcano or a depression produced by a meteorite impact.
• Most craters were produced by the impact of rapidly moving debris.
• Rays are any of a system of bright, elongated streaks, sometimes associated with a crater on the moon.

62. The Moon’s Surface Mare Imbrium (Sea of Rains) Kepler
Mare Tranquillitatus
(Sea of Tranquility)
Mare Imbrium
(Sea of Rains)
Kepler
Crater
Copernicus
Makes no sense without caption in book

63. Formation of a Crater
Makes no sense without caption in book

64. 22.3 Earth’s Moon The Lunar Surface  Highlands  Maria
• Most of the lunar surface is made up of densely pitted, light-colored areas known as highlands.
 Maria
• Maria, ancient beds of basaltic lava, originated when asteroids punctured the lunar surface, letting magma bleed out.
• A rille is a long channel associated with lunar maria. A rille looks similar to a valley or a trench.
1st

65. 22.3 Earth’s Moon The Lunar Surface  Regolith
• The lunar regolith is a thin, gray layer on the surface of the moon, consisting of loosely compacted, fragmented material believed to have been formed by repeated impacts of meteorites.

66. Major Topographic Features of the Moon
Makes no sense without caption in book

67. 22.3 Earth’s Moon Lunar History
 The most widely accepted model for the origin of the moon is that when the solar system was forming, a body the size of Mars impacted Earth. The resulting debris was ejected into space, began orbiting around Earth, and eventually united to form the moon.

68. Formation of Earth’s Moon
Makes no sense without caption in book

69. STARTER
Draw a simple illustration for the motions of Earth: rotation, revolution, & precession

70. Classwork
Draw, color, and label the Major topographic features of the moon’s surface.
List facts about the Lunar Surface and Lunar History.
Using complete sentences answer 1-5 on the section assessment.
Read Foucalt’s Experiment on page 635. Answer the following questions.
Once the pendulum is set in motion, it will continue to swing in the same direction unless it is pushed or pulled by a force. Why is this true?
What outside force is acting on the pendulum?
Why does the pendulum change position over time?
How does this prove that Earth is rotating?
Homework: Study & write a paragraph explaining what evidence scientists use to reconstruct the history of the moon.

71. Classwork
Based on the you vocabulary definitions can you determing the meaning of the following word parts:
1. helios 2. ge or gee peri ap- or apo-
Using Figure 12 on page 623 answer the following questions
What are the reference points for a mean solar day and a sidereal day?
Why do these two reference points give two different results?
Why do astronomers choose to use the sidereal day instead of the mean solar day?

72. Classwork Complete the reading strategy.
Using figure 17 answer the following questions
During a solar eclipse, why do observers in the umbra see a total solar eclipse?
Why do observers in the penumbra see a partial eclipse?
When does a total lunar eclipse occur?
When does a partial lunar eclipse occur?
Using complete sentences answer 1-6 on the section assessment.

73. Classwork Create a Venn diagram on geocentric and heliocentric models
Using Figure 4 answer the following questions
Why does Mars appear to have retrograde motion?
Using Newton’s laws of motion, explain why retrograde motion is impossible.
Using complete sentences answer 1-6 on the section assessment.

74. 22.1 Mini-Quiz What is astronomy? What is the heliocentric model?
What is retrograde motion?
What is Kepler’s 2nd law of motion?
What does Newton’s Law of Universal gravitation take into account that Kepler’s 3rd law doesn’t?

75. 22.2 Mini-Quiz What the two main motions of Earth? What is precession?
What causes the phases of the moon?
Why does one side of the moon always face Earth?
Which shadow do you have to be in to see a total eclipse?

76. 22.3 Mini-Quiz How did the moon most likely form?
Why are craters more likely on the moon than on Earth?
How old are the maria?
What are rilles?
What is lunar regolith?