1. Copyright © 2010 Pearson Education, Inc. What is a planet? http://www.youtube.com/watch?v=RQU 2Q-CU6lYhttp://www.youtube.com/watch?v=RQU 2Q-CU6lY What is a planet? 1. orbits the sun 2. nearly round shape because its own gravity is sufficient 3. neighborhood is cleared because its gravity is sufficient

2. Copyright © 2010 Pearson Education, Inc. What is a dwarf planet? 1. orbits the sun 2. nearly round shape because its own gravity is sufficient 3. neighborhood is not cleared because its gravity is not sufficient 4.Not a moon of another planet

3. Copyright © 2010 Pearson Education, Inc. Chapter 7 The Jovian Planets Why is Jupiter so happy? Now we shift gears from our local rock planets to the outer gas giants. We have in our own solar system 4 examples of each of the types of planets!

4. Copyright © 2010 Pearson Education, Inc. Why name planets after Greek/Roman gods and goddesses? Everything important got a god associated with it. Why Roman took over Greek names? What about dozens of other cultures and myths? Did the Greeks think the god Jupiter was literally in that speck of light? Modern convention in our solar system Rules governed by the IAU http://www.iau.org/http://www.iau.org/

5. Copyright © 2010 Pearson Education, Inc. Mercury is the god of commerce, travel and thievery in Roman mythology. The planet probably received this name because it moves so quickly across the sky. Venus is the Roman goddess of love and beauty. The planet is aptly named since it makes a beautiful sight in the sky, with only the Sun and the Moon being brighter. Earth is the only planet whose English name does not derive from Greek/Roman mythology. The name derives from Old English and Germanic. There are, of course, many other names for our planet in other languages. Mars is the Roman god of War. The planet probably got this name due to its red color. Jupiter was the King of the Gods in Roman mythology, making the name a good choice for what is by far the largest planet in our solar system. Saturn is the Roman god of agriculture. Uranus is the ancient Greek deity of the Heavens, the earliest supreme god. Neptune, was the Roman god of the Sea. Given the beautiful blue color of this planet, the name is an excellent choice! Pluto is the Roman god of the underworld in Roman mythology. Perhaps the planet received this name because it's so far from the Sun that it is in perpetual darkness.

6. Copyright © 2010 Pearson Education, Inc. For the five true planets, their element's Chinese character, hanzi( 汉字 ), is also part of the names of weekdays in Japanese and Korean, complemented with Sunday and Monday. 10 However, Chinese and Vietnamese number the days other than Sunday. 11hanzi weekdaysJapaneseKorean 10Chinese Vietnamese 11 The cycles of the Chinese calendar are linked to the orbit of Jupiter, there being 12 sacred beasts in the Chinese dodecannualar geomantic and astrological cycle, and 12 years in the orbit of Jupiter.Chinese calendar The planets in East Asia cultures

7. Copyright © 2010 Pearson Education, Inc. English Name Associate d elementelement Chinese/J apanese Character s Chinese pinyin pinyin Japanese romaji romaji Korean Name Vietname se Name Old astronomi cal names [12] [12] Mercurywater 水星 ShuǐxīngSuisei 수성 (Suseong ) Sao Thủy Chénxīng ( 辰星 ) Venus metal/gol d 金星 JīnxīngKinsei 금성 (Geumse ong) Sao Kim, also "Sao Mai" as "morning star" and "Sao Hôm" as "evening star"Sao Mai Tàibái ( 太 白 ) Marsfire 火星 HuǒxīngKasei 화성 (Hwaseo ng) Sao Hỏa Yínghuò ( 熒惑 ) Jupiterwood 木星 MùxīngMokusei 목성 (Mokseo ng) Sao Mộc Suì ( 歲 ) Saturnearth 土星 TǔxīngDosei 토성 (Toseong ) Sao Thổ Zhènxīng ( 鎮星 )

8. Copyright © 2010 Pearson Education, Inc. Observations of Jupiter and Saturn The Discoveries of Uranus and Neptune Bulk Properties of the Jovian Planets Jupiter’s Atmosphere The Atmospheres of the Outer Jovian Worlds Jovian Interiors Summary of Chapter 7 Units of Chapter 7

9. Copyright © 2010 Pearson Education, Inc. Our mission Understand the properties of these 4 planets Relate their properties to their origin Compare them to each other Compare them to the rocky inner planets Be able to find Jupiter in the sky, and see its moons with binocs

10. Copyright © 2010 Pearson Education, Inc. Jupiter can be imaged well from Earth, even with a small telescope. Here: Jupiter with its Galilean moons 7.1 Observations of Jupiter and Saturn Do you have binoculars?

11. Copyright © 2010 Pearson Education, Inc. True-color image of Jupiter 19 jan..7.1 Observations of Jupiter and Saturn This image is from Hubble, but much of our Jupiter knowledge is from the Galileo probe which cost $1.6b over 16 years http://www.dailymotion.com/vide o/xeaio4_learn-about-the- discoveries-of-the_tech

12. Copyright © 2010 Pearson Education, Inc. Natural-color image of Saturn 7.1 Observations of Jupiter and Saturn Saturn has a thick atmosphere: why can we see it so clearly?

13. Copyright © 2010 Pearson Education, Inc. Cassini image of Jupiter, true color 7.1 Observations of Jupiter and Saturn

14. Copyright © 2010 Pearson Education, Inc. The Cassini mission: Wow! Look at nasa site and wikipedia Here’s a nice TED talk http://www.ted.com/talks/carolyn_porco _flies_us_to_saturn.html http://www.ted.com/talks/carolyn_porco _flies_us_to_saturn.html

15. Copyright © 2010 Pearson Education, Inc. Uranus, in natural color. Note the absence of features and the prevalence of beauty. 23 Jan: 7.2 The Discoveries of Uranus and Neptune How was Uranus discovered?

16. Copyright © 2010 Pearson Education, Inc. Neptune in natural color 7.2 The Discoveries of Uranus and Neptune How was Neptune discovered and how was this different from every other planet so far?

17. Copyright © 2010 Pearson Education, Inc. The Jovian planets are large and much less dense than the terrestrial planets; Saturn is less dense than water! 7.3 Bulk Properties of the Jovian Planets None have a solid surface at all, although all have a dense core more massive than earth? explain that!

18. Copyright © 2010 Pearson Education, Inc. Jovian planets, compared to Earth 7.3 Bulk Properties of the Jovian Planets Where is the snowball that started each planet?

19. Copyright © 2010 Pearson Education, Inc. Peculiarity of Uranus: Axis of rotation lies almost in the plane of its orbit. Seasonal variations are extreme. 7.3 Bulk Properties of the Jovian Planets

20. Copyright © 2010 Pearson Education, Inc. Galileo spacecraft http://en.wikipedia.org/wiki/Galileo_(spacecraft) http://www.dailymotion.com/video/xeaio4_learn- about-the-discoveries-of-the_techhttp://www.dailymotion.com/video/xeaio4_learn- about-the-discoveries-of-the_tech

21. Copyright © 2010 Pearson Education, Inc. Atmosphere has bright zones and dark belts. Zones are cooler, and are higher than belts. Stable flow underlies zones and bands, called zonal flow. Simplified model: 7.4 Jupiter’s Atmosphere

22. Copyright © 2010 Pearson Education, Inc. No solid surface; take top of troposphere to be 0 km. Lowest cloud layer cannot be seen by optical telescopes. Measurements by Galileo probe show high wind speeds even at great depth – probably due to heating from planet, not from Sun. 7.4 Jupiter’s Atmosphere Why this composition?

23. Copyright © 2010 Pearson Education, Inc. The Galileo probe descended into Jupiter’s atmosphere and returned valuable data. The arrow indicates its entry point. 7.4 Jupiter’s Atmosphere What is difference between gas atmosphere and clouds?

24. Copyright © 2010 Pearson Education, Inc. Major visible features: Bands of clouds; Great Red Spot 7.4 Jupiter’s Atmosphere A hurricane that is several hundred years old, 2x the diameter of earth Shown actual size!

25. Copyright © 2010 Pearson Education, Inc. Two examples of smaller storms merging, first into a smaller red spot, second into existing Great Red Spot 7.4 Jupiter’s Atmosphere Check: write a weather forcast for Jupiter….

26. Copyright © 2010 Pearson Education, Inc. The atmosphere of Saturn is similar to that of Jupiter, except that Saturn is somewhat colder and its atmosphere is thicker. 7.5 The Atmospheres of the Outer Jovian Worlds

27. Copyright © 2010 Pearson Education, Inc. Saturn’s atmosphere is similar to Jupiter’s, except pressure is lower. It has three cloud layers. Cloud layers are thicker than Jupiter’s; see only top layer. 7.5 The Atmospheres of the Outer Jovian Worlds

28. Copyright © 2010 Pearson Education, Inc. Saturn also has large storms, and bands. 7.5 The Atmospheres of the Outer Jovian Worlds

29. Copyright © 2010 Pearson Education, Inc. Storms near Saturn’s equator 7.5 The Atmospheres of the Outer Jovian Worlds Evidence of lightning

30. Copyright © 2010 Pearson Education, Inc. Enormous thunderstorm on Saturn 7.5 The Atmospheres of the Outer Jovian Worlds

31. Copyright © 2010 Pearson Education, Inc. Rotation of Uranus can be measured by watching storms. 7.5 The Atmospheres of the Outer Jovian Worlds

32. Copyright © 2010 Pearson Education, Inc. Neptune has storm systems similar to those on Jupiter, but fewer. The large storm system at top has disappeared in recent years. 7.5 The Atmospheres of the Outer Jovian Worlds

33. Copyright © 2010 Pearson Education, Inc. No direct information is available about Jupiter’s interior, but its main components, hydrogen and helium, are quite well understood. The central portion is thought to be a rocky core. 7.6 Jovian Interiors

34. Copyright © 2010 Pearson Education, Inc. Magnetic fields of Uranus and Neptune must not be produced by dynamos, as the other planets’ fields are. Interior structure of Uranus and Neptune, compared to that of Jupiter and Saturn: 7.6 Jovian Interiors

35. Copyright © 2010 Pearson Education, Inc. Jupiter’s magnetosphere: Intrinsic field strength is 20,000 times that of Earth. Magnetosphere can extend beyond the orbit of Saturn. 7.6 Jovian Interiors So catching solar wind in a magnetic field should lead to….?

36. Copyright © 2010 Pearson Education, Inc. Aurorae are seen on Jupiter, and have the same cause as those on Earth – the interaction of solar wind particles with the magnetosphere. 7.6 Jovian Interiors

37. Copyright © 2010 Pearson Education, Inc. Uranus and Neptune both have substantial magnetic fields, but at a large angle to their rotation axes. The rectangle within each planet shows a bar magnet that would produce a similar field. Note that both Uranus’s and Neptune’s are significantly off center. 7.6 Jovian Interiors

38. Copyright © 2010 Pearson Education, Inc. Jovians in the news P208. a cometary impact

39. Copyright © 2010 Pearson Education, Inc. Summary of Chapter 7 Jupiter and Saturn were known to the ancients; Uranus was discovered by chance, and Neptune was predicted from anomalies in the orbit of Uranus. Jovian planets are large but not dense; they are fluid and display differential rotation. Cloud layers have light zones and dark bands; wind pattern, called zonal flow, is stable.

40. Copyright © 2010 Pearson Education, Inc. Summary of Chapter 7, cont. Storms appear with regularity; the Great Red Spot of Jupiter has lasted for hundreds of years (that we know of). Due to conductive interiors and rapid rotation, Jovian planets have large magnetic fields. Jupiter, Saturn, and Neptune radiate more energy than they receive from the Sun.

41. Copyright © 2010 Pearson Education, Inc. A few points in addition to know. Why do they hold gas? Massive, magnetosphere, and far from sun Why are they still losing heat? Still cooling from the big compression 4+ billion years ago Properties of atmospheres? Layers, clouds, rotation

42. Copyright © 2010 Pearson Education, Inc. How are jovians different from terrestrials to attain their structure? Past frost line, snowball and high gravity early Gas was pushed out to them Nevertheless, they still collected dust and debris which is buried under gas