Planets and the Solar System: Chapter 27 Overview

2. Earth Warm Up Ch. 27 • Does Mars have an atmosphere? If so…what is it made of? • What is a major difference between the Terrestrial planets and the Jovian planets? • Which planet has caps of frozen Carbon dioxide? • Explain the structure of Jupiter? • Name 4 of Jupiter’s moons?

4. Warm Up Ch. 27 • What is Pluto and Mercury’s orbit inclination? • The force of gravitation between 2 objects depends on what? • Why does Mercury have no atmosphere? • Why is Venus so hot? • Why is it difficult to achieve nuclear fusion except in the center of stars?

5. The Planets and The Solar System Chapter 27

6. Overview of the solar system • Solar system includes • Sun • Nine planets and their satellites • Asteroids • Comets • Meteoroids

7. The solar system

8. A planet's orbit lies in an orbital plane • Similar to a flat sheet of paper • The orbital planes of the planets are inclined • Planes of seven planets lie within 3 degrees of the Sun's equator • Mercury's is inclined 7 degrees • Pluto's is inclined 17 degrees

9. Two groups of planets occur in the solar system • Terrestrial (Earth-like) planets • Mercury through Mars • Small, dense, rocky • Low escape velocities

10. Two groups of planets occur in the solar system • Jovian (Jupiter-like) planets • Jupiter through Neptune • Large, low density, gaseous • Massive • Thick atmospheres • Pluto not included in either group

11. The planets drawn to scale

12. Evolution of the planets • Nebular hypothesis • Our planets formed about 5 billion years ago • Solar system condensed from a gaseous nebula

14. Evolution of the planets • Nebular hypothesis • Planets formed about 5 billion years ago • Solar system condensed from a gaseous nebula • As the planets formed, the materials that compose them separated

15. Due to their surface gravities, Venus and Earth retained atmospheric gases • Due to frigid temperatures, the Jovian planets contain a high percentage of ices

16. END OF LECTURE

17. Mercury • Closest to the sun which makes its orbit the shortest • 1 Mercury year = 88 Earth days • 1 Mercury day = 58 Earth days • Has no atmosphere because it has weak gravity • Day temps = 400+ degrees C • Night temps = -200 degrees C • Its surface has craters and plains (due to previous volcanic flow)

18. Photomosaic of Mercury

20. Venus • Second to the Moon in brilliance • Similar to Earth in • Size, Density, and location • Shrouded in thick clouds • Impenetrable by visible light • Atmosphere is 97% carbon dioxide • Surface atmospheric pressure is 90 times that of Earth's

21. Computer generated view of Venus

23. Mars • Called the "Red Planet" • Atmosphere • 1% as dense as Earth's • Primarily carbon dioxide • Polar caps of water ice, covered by a thin layer of frozen carbon dioxide

24. A picture of the Martian landscape from the Viking 1 lander

25. Mars • Surface • Numerous large volcanoes – largest is Mons Olympus • Less-abundant impact craters • Tectonically dead • Several canyons • Some larger than Grand Canyon

26. Mons Olympus, an inactive shield volcano on Mars

27. The Valles Marineris canyon system on Mars

28. Mars • Moons • Two moons • Phobos • Deimos • Captured asteroids

30. c Scale Model -Earth, Venus, Mars, Mercury and [the little gray one] the moon

31. Jupiter • Largest planet • 2.5 more massive than combined mass of the planets, satellites, and asteroids • If it had been ten times larger, it would have been a small star • Rapid rotation • Slightly less than 10 hours • Slightly bulged equatorial region

32. END OF LECTURE

34. Artist’s view of Jupiter with the Great Red Spot visible

35. Infrared image of Jupiter

36. Jupiter • Banded appearance • Multicolored • Bands are aligned parallel to Jupiter's equator • Generated by wind systems • Great Red Spot • In planet's southern hemisphere • Counterclockwise rotating cyclonic storm

37. Jupiter • Structure • Surface thought to be a gigantic ocean of liquid hydrogen • Halfway into the interior, pressure causes liquid hydrogen to turn into liquid metallic hydrogen • Rocky and metallic material probably exists in a central core

38. Jupiter • Moons • At least 67 moons • Four largest moons • Discovered by Galileo • Called Galilean satellites

39. Callisto – outermost moon • Europa – smallest moon • Ganymede - largest Jovian satellite • Io - innermost Galilean moon and is also volcanically active

40. A volcanic eruption on Io

41. Saturn • Similar to Jupiter in its • Atmosphere • Composition • Internal structure • Rings • Most prominent feature • Discovered by Galileo in 1610 • Complex

42. Saturn • Rings • Composed of small particles (moonlets) that orbit the planet • Most rings fall into one of two categories based on particle density • Thought to be debris ejected from moons • Origin is still being debated

44. Saturn • Other features • Dynamic atmosphere • Large cyclonic storms similar to Jupiter's Great Red Spot • 67 named moons

45. Titan – the largest Saturnian moon • Second largest moon (after Jupiter's Ganymede) in the solar system • Has a substantial atmosphere

46. Uranus • Uranus and Neptune are nearly twins • Rotates "on its side" • Rings • 27 moons discovered so far • Large moons have varied terrains

47. Neptune • Dynamic atmosphere • One of the windiest places in the solar system • Great Dark Spot • 13 satellites • Triton – largest Neptune moon • Orbit is opposite direction • Lowest surface temperature in the solar system (-391ºF)

48. Scale model --[from left, back row] Jupiter, Saturn,[middle row]:Uranus, Neptune,and then the little ones in front row, from left:Earth, Venus, Mars, Mercury and the moon

49. Pluto • Not visible with the unaided eye • Discovered in 1930 • Highly elongated orbit causes it to occasionally travel inside the orbit of Neptune, where it resided from 1979 thru February 1999 • Moon (Charon) discovered in 1978 • Could be a double planet • Average temperature is -210ºC

50. Pluto and its moon Charon as compared to the size of Earth