1 / 45

Chapter 7 Our Planetary System

Chapter 7 Our Planetary System. Earth, as viewed by the Voyager spacecraft. What does the solar system look like?. Eight major planets with nearly circular orbits Pluto is smaller than the major planets and has a more elliptical orbit.

alma-kirkland
Download Presentation

Chapter 7 Our Planetary System

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 7Our Planetary System Earth, as viewed by the Voyager spacecraft

  2. What does the solar system look like?

  3. Eight major planets with nearly circular orbits • Pluto is smaller than the major planets and has a more elliptical orbit

  4. Planets all orbit in same direction and nearly in same plane http://observe.phy.sfasu.edu/courses/ast105/lectures105/chapter06/orbit_and_rotation_planets.htm

  5. Thought QuestionHow does the Earth-Sun distance (1AU) compare with the Sun’s radius • It’s about 10 times larger. • It’s about 50 times larger. • It’s about 200 times larger. • It’s about 1000 times larger.

  6. Thought QuestionHow does the Earth-Sun distance compare with the Sun’s radius • It’s about 10 times larger. • It’s about 50 times larger. • It’s about 200 times larger. • It’s about 1000 times larger.

  7. Bode’s Law • a simple rule that gives the distances of the planets from the Sun where N=0, 3, 6, 12, 24…for Mercury, Venus, Earth, Mars, etc.

  8. Planet N Bode’s Law Radii True Orbital Radii Mercury 0 (0+4)/10 = 0.4 AU 0.39 AU Venus 3 (3+4)/10 = 0.7 AU 0.72 AU Earth 6 (6+4)/10 = 1.0 AU 1.00 AU Mars 12 (12+4)/10 = 1.6 AU 1.52 AU ____ 24 (24+4)/10 = 2.8 AU _______ Ceres 24 2.88 AU Jupiter 48 (48+4)/10 = 5.2 AU 5.2 AU Saturn 96 (96+4)/10 = 10.0 AU 9.5 AU Uranus 192 (192+4)/10 = 19.6 AU 19.2 AU Neptune ? ? 30.1 AU Pluto 384 (384+4)/10 = 38.8 AU 39.5 AU

  9. What does Bode’s Law tell us? • Bode's Law predicted that there should be a planet between the orbits of Mars and Jupiter. • The "missing planet" turned out to be the asteroid belt.

  10. What are the major features of the Sun and planets? Sun and planets to scale

  11. What to know Main features – Rock or Gas? Color? Rings? Clouds? Moons? – Names of major moons Anything else that is odd or intersting.

  12. Planets are very tiny compared to distances between them.

  13. Sun • Over 99.9% of solar system’s mass • Made mostly of H/He gas (plasma) • Converts 4 million tons of mass into energy each second

  14. Mercury • Made of metal and rock; large iron core • Desolate, cratered; long, tall, steep cliffs • Very hot and very cold: 425°C (day), –170°C (night) • No atmosphere • Only slightly larger than Earth’s Moon.

  15. Venus • Nearly identical in size to Earth; surface hidden by clouds • Hellish conditions due to an extreme greenhouse effect: • Even hotter than Mercury: 470°C, day and night

  16. Earth Earth and Moon to scale • An oasis of life • The only surface liquid water in the solar system • A surprisingly large moon

  17. The Moon • Many craters • Maria

  18. Mars • Looks almost Earth-like, knee high atmosphere • Giant volcanoes (Olympus Mons), a huge canyon (Valles Marineris), and polar caps (CO2). • Water flowed in the distant past; could there have been life?

  19. Moons of Mars • Two small moons • Phobos – Greek for fear • Deimos- Greek for dread or panic

  20. Jupiter • Much farther from Sun than inner planets • Mostly H/He; no solid surface • 300 times more massive than Earth • Great Red Spot • Many moons (60+), rings …

  21. Jupiter’s moons can be as interesting as planets themselves, especially Jupiter’s four Galilean moons • Io (shown here): Active volcanoes all over • Europa: Possible subsurface ocean • Ganymede: Largest moon in solar system • Callisto: A large, cratered “ice ball”

  22. Jupiter has a thin ice ring.

  23. Saturn • Giant and gaseous like Jupiter • Spectacular rings – Cassini’s Division • Many moons, including cloudy Titan • Cassini spacecraft currently studying it

  24. Rings are NOT solid; they are made of countless small chunks of ice and rock, each orbiting like a tiny moon. Artist’s conception

  25. Cassini probe arrived July 2004 (Launched in 1997)

  26. Uranus • Smaller than Jupiter/Saturn; much larger than Earth • Made of H/He gas & hydrogen compounds (H2O, NH3, CH4) • Extreme axis tilt • Moons & rings

  27. Neptune • Similar to Uranus (except for axis tilt) • Great Dark Spot • Many moons (including Triton)

  28. Pluto (Not a Planet and not Red) • Much smaller than any of the planets • Icy, comet-like composition • Its moon Charon is similar in size

  29. Thought QuestionWhat process created the elements from which the terrestrial planets were made? • The Big Bang • Nuclear fusion in stars • Chemical processes in interstellar clouds • Their origin is unknown

  30. What have we learned? • What are the major features of the Sun and planets? • Sun: Over 99.9% of the mass • Mercury: A hot rock • Venus: Same size as Earth but much hotter • Earth: Only planet with liquid water on surface • Mars: Could have had liquid water in past • Jupiter: A gaseous giant with the great red spot • Saturn: Gaseous with spectacular rings • Uranus: A gas giant with a highly tilted axis • Neptune: Gas giant with great dark spot • Pluto: An icy “misfit” more like a comet than a planet

  31. What features of the solar system provide clues to how it formed?

  32. Motion of Large Bodies • All large bodies in the solar system orbit in the same direction and in nearly the same plane • Most also rotate in that direction

  33. Two Main Planet Types • Terrestrial planets are rocky, relatively small, and close to the Sun • Jovian planets are gaseous, larger, and farther from Sun

  34. Swarms of Smaller Bodies • Many rocky asteroids and icy comets populate the solar system

  35. Notable Exceptions • Several exceptions to the normal patterns need to be explained

  36. Special Topic: How did we learn the scale of the solar system?

  37. Transit of Venus • Apparent position of Venus on Sun during transit depends on distances in solar system and your position on Earth Transit of Venus: June 8, 2004

  38. Measuring Distance to Venus • Measure apparent position of Venus on Sun from two locations on Earth • Use trigonometry to determine Venus’ distance from the distance between the two locations on Earth

  39. How do robotic spacecraft work?

  40. Flybys • A flyby mission flies by a planet just once • Cheaper than other mission but have less time to gather data

  41. Orbiters • Go into orbit around another world • More time to gather data but cannot obtain detailed information about world’s surface

  42. Probes or Landers • Land on surface of another world • Explore surface in detail

  43. Sample Return Missions • Land on surface of another world • Gather samples • Spacecraft designed to blast off other world and return to Earth • Apollo missions to Moon are only sample return missions to date

  44. Combination Spacecraft • Cassini/Huygens mission contains both an orbiter (Cassini) and a lander (Huygens)

More Related