Chapter 4 The Sun, Planets and Other bodies

1. Chapter 4 The Sun, Planets and Other bodies

2. I. The structure of the sun. • The sun appears to be solid. • The surface of the sun begins where the gas is so thick that you cannot see through it. 1. Like fog

3. C. Layers of the sun • The corona is the outer layer of the sun • The Chromosphere is a thin region of the corona only 30,000 km thick • The photosphere is the visible part of the sun that we can see from Earth.

4. 4. The convective Zone is a region about 200,000 km thick where the gases circulate 5. The Radiative zone is a very dense region about 300,000 thick. 6. The core is at the center of the sun is this is where the energy is produced (fussion happens here)

5. II. Energy Production in the Sun 1. About 4.6 billion years old

6. A. Burning or Shrinking? • There are two theories on how it could burn for so long. • Some type of burning fuel was thought to be the source (like a fire)

7. b. The sun was shrinking due to gravity c. The gravity released enough energy to heat the sun i. If this were the case the sun would only last for 46 million years. ii. Fossils have proven otherwise.

8. B. Nuclear Fusion • Albert Einstein showed that matter and energy are interchangeable • Matter can change into energy according to E=mc2 a. E= energy, m= mass, and c = speed of light. b. Because c is such a large number a small amount of mass can produce a huge amount of energy.

9. 3. Nuclear fusion is the process by which 2 or more low-mass nuclei join together, or fuse to form another nucleus.

10. C. Fusion in the Sun 1. Under normal conditions the nuclei of hydrogen atoms never get close enough to combine.

11. This is because they are positively charged. • In the sun the temperature and the pressure are very high • Because they are positively charged they want to push apart from each other. • They overcome this force and fuse together to become helium

12. 2. This happens in the Radiative zone 3. Eventually the energy will reach the convective zone

13. D. Solar Activity a. The movement of energy cause the gas in the photosphere to boil and churn

14. 1. Sunspots. a. Sunspots are cooler, dark spots of the photosphere b. Can be as large as 50,000 miles in diameter c. Scientists have found that about every 11 years the amount of sunspot reaches a peak in its intensity and then decreases.

15. 2. Climate confusion a. The sunspot activity directly affects the climate on the earth. When the activity is high the temperatures are high on Earth.

16. 3. Solar Flares a. The magnetic fields that are around the sun cause not only sunspots but also solar flares. b. These are regions of extremely high temperatures and brightness that develop on the sun’s surface

17. c. It sends out a huge stream of electrically charged particles into the solar system d. They can extend several thousand km in minutes. e. They can interrupt radio communications on Earth and in orbit f. They currently cannot be predicted.

19. Section 3: The 9 planets

20. I. Our Solar System A. The word planets means “wanderers” in Greek.

21. II. Measuring Interplanetary distances A. Too small of a distance for light years

22. B. Scientists use astronomical unit. 1. Average distance between the sun and the earth 2. Aprox. 150,000,000 km

23. C. Light minute 1. The distance light travels in one minute. 2. 18,000,000 km 3. So the distance from the Earth to the Sun is 8.3 light-minutes or 1 AU

24. D. The discovery of the Solar system 1. Until the 1600’s the universe was thought to only have eight bodies 2. 1700’s Uranus and 2 moons of Saturn and several other planets were found 3. Pluto was found in the 1900’s

25. Section 4: The Inner Planets

26. I. Mercury: Closest to the Sun A. Much less gravity 1. You would weight only 38% of what you do now.

27. B. Rotates very slow 1. 58 days, 19 hours on Earth = 1 day on Mercury a. The time it takes to rotate once is called a period of rotation. 2. A years on Mercury is only 88 Earth days long a. A year is called a period of revolution. b. Mercury’s period of revolution is every 1.5 Mercurian days

28. 3. Distance from the sun 3.2 Light- minutes from the sun 4. Diameter 4,879 km 5. Surface temperature -173 Celsius to 427 Celsius.

30. II. Venus: Earth’s Twin • Venus is very much like Earth. But it is smaller a). 12,104 KM 2. Sun rises in the West and sets in the East. a). This is called retrograde rotation (backwards)

31. A. The Atmosphere of Venus • Venus has the densest atmosphere of all the terrestrial planets. • It has 90 times the pressure of Earth. • Mostly Carbon dioxide but also made up of acids.

32. 4. The CO2 traps in thermal energy and causes the greenhouse effect. 5. Hottest planet in the solar system. a). 464 degrees Celsius

33. B. Mapping Venus’s Surface 1. Between 1990 and 1992 the Magellan spacecraft mapped the surface of Venus by using radar waves. 2. This showed that like Earth Venus has volcanoes.

34. C. Other Facts about Venus 1. 91% of the Gravity of Earth 2. 12,104 KM diameter 3. Years is 224 days and 17 hours 4. Period of rotation is 243 days and 16 hours 5. Day is longer than its year

36. III. Earth: An Oasis in Space 1. Constantly changing weather patterns create swirls of clouds A. Water on Earth 1. Perfect distance from the Sun to keep water from freezing. 2. Not to warm either to keep it from boiling away.

37. B. Other Facts about Earth. • 8.3 light-minutes from sun • Period of rotation is 23 hours and 56 mins. • Diameter is 12,759 KM • Surface temperature is -13 to 37 Celsuis

39. IV.Mars: Our intriguing Neighbor A. Much of our knowledge of Mars has come from information gathered from spacecraft. 1. Viking one and 2 landed on mars in 1976 2. Mars Pathfinder landed on Mars in 1997

40. 2. The atmosphere of Mars A. Very thin atmosphere and great distance from the sun • This makes Mars very cold. • -123 Celsius to 37 Celsius • Midsummer temperature recorded by Pathfinder from -13 to -77 Celsius.

41. b. Pressure is so low that any liquid water would instantly boil. c. Only water is in Ice form

42. 3. Water on Mars. a). Even though there is no liquid water on Mars there is evidence that it existed there in the past 4. Where is the Water Now? • Mars has 2 polar icecaps made of frozen water and carbon dioxide • Some craters look like that have been formed by mud rather than dry soil.

43. 5. Martian Volcanoes • Mars has 2 large volcanic systems • Tharsis is the larder and stretches 8,000 Km across the planet. • The largest mountain is here and is called Olympus. • Mars is made of different chemicals than earth. The crust does not move like Earth’s. Thus, the volcanoes keep building up in the same spots.

44. 6. Missions to Mars • Scientists are intrigued by the mysteries of Mars

45. 7. Other Martian Facts • 12.7 light-minutes from the sun • Day is 24 hours and 40 mins. • Year is 1 year and 322 Earth days • Diameter is 6,794 KM • 38% of Earth’s gravity

47. Section 5: The Outer planets

48. Jupiter: A Giant among Giants • Jupiter is the largest planet in our solar system • Just like the sun it is mostly clouds of hydrogen and helium. • The outer clouds are likely to be made of water methane and ammonia.

49. 4. At 10,000 KM deep into Jupiter’s atmosphere the pressure is enough to make hydrogen gas into a liquid. 5. Jupiter puts out more energy than it gets from the Sun. 6. The “red spot” is a storm that is more than 400 years old and about 3 times the diameter of the earth

50. A. NASA missions to Jupiter • Voyager 1 and 2 sent pictures back that show a faint ring around Jupiter • They also sent images back of Jupiter’s moons. • Galileo reached Jupiter in 1995 and sent a probe into the atmosphere a. This probe sent back info on the composition, temperature and pressure.