1. Chapter 2 The Solar System
Section 1 Observing the Solar System

2. Ch. 2, section 1 Observing the Solar System Objectives
Explain how the heliocentric and geocentric models of the solar system differ
Describe Kepler’s discovery about the planet’s orbit
Identify two factors that keep the planets in their orbits.

3. Geocentric A description of the solar system in which all of the planets revolve around Earth.

4. 2. Heliocentric A description of the solar system in which all of the planets revolve around the sun.

5. 3. Ellipse An elongated circle, or oval shape.

6. 4. Inertia The tendency of a moving object to continue in a straight line or a stationary object to remain in place.

7. 1. In a _________________, Earth is at the center of the revolving planets.
geocentric system

8. 2. In a _________________, Earth and the other planets revolve around the sun.
heliocentric system

9. 3. Galileo’s two discoveries to support the heliocentric system were: - he saw __________ ___________ revolving around Jupiter. - he also saw that ____________ goes through phases similar to those of Earth’s moon
four
moons
Venus

10. 4. Kepler discovered that the orbit of each planet is an __________.
ellipse

11. 5. Newton concluded that two factors: _________ and __________ combine to keep the planets in orbit.
inertia
gravity

12. Chapter 2 The Solar System
Section 2 The Sun

13. Ch. 2, section 2 The Sun Objectives
Explain how the sun gets its energy
Identify the layers of the sun’s atmosphere
Describe some features of the sun’s surface

14. Nuclear Fusion The process by which hydrogen atoms join together to form helium, releasing energy.

15. Core The central part of the sun, where nuclear fusion occurs.

16. 3. Photosphere The inner layer of the sun’s atmosphere.

17. 4. Chromosphere The middle layer of the sun’s atmosphere.

18. 5. Corona The outer layer of the sun’s atmosphere.

19. 6. Solar wind A stream of electrically charged particles produced by the sun’s corona.

20. 7. Sunspot A dark area of gas on the sun that is cooler than surrounding gases.

21. 8. Prominence A loop of gas that protrudes from the sun’s surface, linking parts of sunspot regions.

22. 9. Solar flare An explosion of hydrogen gas from the sun’s surface that occurs when loops in sunspot regions suddenly connect.

23. 1. The sun’s __________ comes from nuclear fusion.
energy

24. 2. Nuclear fusion takes place in the sun’s _________.
core

25. 3. The sun’s atmosphere has three layers: the ____________, the ____________, and the __________.
photosphere
chromosphere
corona

26. 4. During a _______________, you can see light from the corona.
total solar eclipse

27. 5. Features on or above the sun’s surface include ___________, _____________, and ____________.
sunspots
prominences
solar flares

28. Chapter 2 The Solar System
Section 3 The Inner Planets

29. Ch. 2, section 3. The Inner Planets Objectives:
Describe the main characteristics of the inner planets.

30. Terrestrial planets The name given to the four inner planets: Mercury, Venus, Earth, and Mars.

31. 2. Retrograde rotation The spinning motion of a planet from east to west, opposite to the direction of rotation of most planets and moons.

32. 3. Greenhouse effect The trapping of heat by a planet’s atmosphere.

33. 1. The four inner planets are ___________, _________, __________, and ___________.
Mercury
Venus
Earth
Mars

34. 2. The four inner planets are __________ and have _________ surfaces.
small
rocky

35. 3. The planet closest to the sun is __________.
Mercury

36. 4. Mercury has an extremely _________ atmosphere.
thin

37. 5. Venus rotates from __________ to _________, the opposite direction from most other planets and moons.
east
west

38. 6. The atmosphere of Venus is so _________ that every day is a __________ one.
thick
cloudy

39. 7. Astronomers have found that some water remains on Mars in the form of ___________ at its north pole.
ice

40. Chapter 2 The Solar System
Section 4 The Outer Planets

41. Ch. 2, section 4. The outer planets Objectives
Describe the main characteristics of the gas giant planets
Explain how Pluto differs from the outer planets

42. Gas Giants The name given to the four outer planets: Jupiter, Saturn, Uranus, and Neptune.

43. 1. The four outer planets are __________, _________, __________, and ___________.
Jupiter
Saturn
Uranus
Neptune

44. 2. Because the gas giants have so much mass, they exert a much stronger ____________ ___________ than the terrestrial planets.
gravitational
force

45. 3. The four outer planets have deep _____________.
atmospheres

46. 4. None of the gas giants has a __________ _________.
solid
surface

47. 5. An especially interesting feature in Jupiter’s atmosphere is its ________ _________ ________.
Great
Red
Spot

48. 6. Jupiter’s four moons are ______, _______, __________, and _________.
Europa Io
Ganymede
Callisto

49. 7. Saturn’s rings are made of chunks of _________ and __________, each traveling in its own orbit.
ice
rock

50. 8. Strangely, Uranus’s axis is tilted at an angle of about ___________ from the vertical.
90 degrees

51. 9. Viewed from Earth, Uranus is rotating from ________ to _________ instead of from _________ to ___________.
top
bottom
side
side

52. 10. The planet Neptune was discovered as a result of a ____________ ___________.
mathematical
prediction

53. Chapter 2 The Solar System
Section 5 Comets, Asteroids, and Meteors

54. Ch. 2, section 5 Comets, Asteroids, and Meteors Objectives
Describe the characteristics of comets and asteroids
Identify where meteoroids come from

55. Comet A ball of ice and dust whose orbit is a long, narrow ellipse.

56. 2. Asteroids Objects revolving around the sun that are too small and too numerous to be considered planets.

57. 3. Asteroid belt The region of the solar system between the orbits of Mars and Jupiter, where many asteroids are found.

58. 4. Meteoroid A chunk of rock or dust in space.

59. 5. Meteor A streak of light in the sky produced by the burning of a meteoroid in Earth’s atmosphere.

60. 6. Meteorite A meteoroid that has hit Earth’s surface.

61. 1. Comets are chunks of _________ and _________ whose orbits are usually very long , narrow ellipses.
ice
dust

62. 2. Most asteroids revolve around the sun between the orbits of _________ and __________.
Mars
Jupiter

63. 3. ___________ usually come from comets or asteroids.
Meteoroids

64. 4. Meteoroids that enter the Earth’s atmosphere are called ___________.
meteors

65. 5. Meteoroids that pass through the atmosphere and hit Earth’s surface are called __________.
meteorites

66. Section 5 reading. Video: Part 1: (9:22 minutes)
Part 2 (10:20 minutes)

67. Chapter 2 The Solar System
Section 6 Is There Life Beyond Earth?

68. Ch. 2, section 6 Is There Life Beyond Earth? Objectives
Describe what living things need to exist on Earth
Explain why scientists are looking at Mars and Europa for signs of life

69. Extraterrestrial life Life that arises outside of Earth.

70. 1. Earth has ___________ and a ___________________ and ___________ for living things to survive.
liquid water
suitable temp. range
atmosphere

71. 2. Since life as we know it requires __________, scientists hypothesize that ________ may have once had the conditions needed for life to exist.
water
Mars

72. 3. If there is liquid water on ________, there might also be life.
Europa