Motions of the Planets

1. Motions of the Planets

2. The Planets

3. Rotation of Planets

4. Terrestrial Planets Rocky Surfaces

5. Mercury

6. Venus

7. Earth

8. Mars – The Red Planet Olympus-Mons Volcano

9. Jovian Planaets The Gas Giants

10. Jupiter At last count, Jupiter has 63 moons.

11. Saturn

12. Uranus – The “U” Planet

13. Neptune

14. Pluto, The Dwarf Planet As it might be seen from it’s moon (Charon)

15. The Asteroid Belt

16. Asteroids

17. Asteroid Impacts

18. Asteroid Impacts

19. Barringer Crater, AZ

20. Also Known as “Meteor Crater” • Width: 1 mi (1.2 km) • Depth: 570 ft (175 m) • Created by the impact of a 50 m wide iron meteor 50,000 yrs. ago

21. Chicxulub – An Extinction Event

22. Why Doesn’t Earth Have Craters Like the Moon?

23. A. Two Views of Planetary Motion in the Solar System Geocentric Model 1. ________________________

24. Claudius Ptolemaeus (Ptolemy)The Geocentric Model • Ptolemy was • An Astronomer • A mathematician • A geographer • Second Century AD • View accepted until 1543

25. The Geocentric Model

26. Geocentric Model Summary • Based on celestial observations from Earth, it was thought by early civilizations (and up through the Renaissance) that (1) Earth was located at the ________of the solar system and is motionless (2) Stars were located on a transparent sphere that rotated each day from ________________. (3) The Sun, moon, and each planet were carried by separate spheres. (4) Each planet is located on an __________that rotates at a fixed rate. This was to explain the phenomenon of ____________motion. b. This is the model advanced by the Greek astronomy Ptolemy (Claudius Ptolemaeus) in the second century. center east to west epicycle retrograde

27. 2. Difficulties with the Geocentric Model • Through the centuries, as more and more data accumulated, the astronomers kept adjusting the model to make it work better. • By 1500 the model had become very complicated and it still didn’t work well. • And, it’s not correct!

28. 2. ____________________ Heliocentric Model

29. Heliocentric Model:Nicolaus Copernicus • An astronomer and mathematician • Niclas Kopernik (his Polish name) • Copernicus is his latinized name • 1473-1543

30. Heliocentric Model Summary Sun • The planets revolve around the. b. Polish astronomer Nicolas Copernicus proposed this model in 1543. c. It would be many years until the modern model of the solar system was refined. Copernicus had the Sun in the exact center of the solar system and the planets revolving in perfect circles. This was later shown to be incorrect by Kepler. d. Accounts formotion of planets. retrograde

31. Galileo Galilei (1564 -1642) • Galileo pioneered "experimental scientific method" and was the first to use a refracting telescope to a series of profound discoveries.

32. Galileo became an Outspoken Supporter of the Copernican Theory • Galileo's observations with his new convinced him of the truth of Copernicus's sun-centered or heliocentric theory. • The Galilean moon system was the first discovery of a center of motion not apparently centered on the Earth. • It was a major point in favor of Copernicus's heliocentric theory of the motions of the planets.

33. B.Kepler’s Laws of Planetary Motion Johannes Kepler 1571 - 1630 Kepler’s View of the Solar System • Used the accumulated data of Danish nobleman • Tycho Brahe to develop three laws of planetary motion

34. Tycho Brahe (1546 – 1601) • Credited with the most accurate astronomical observations of his time (before the invention of the telescope) • Established the Research Institute of Uraniborg on the Island of Hven between Denmark and Sweden. • Kepler was Tycho’s assistant

35. 1. Kepler’s First Law of Planetary Motion • The orbit of each planet around the Sun is an __________ • The Sun is located at a _________within the elliptical orbit and is not at the exact center of the orbit ellipse focus

36. 2. Kepler’s Second Law of Planetary Motion • Each planet moves around the Sun so that an imaginary line ( _____________)joining the planet and the Sun will sweep over ________________________. radius vector equal areas in equal times

37. This means that because the orbits are elliptical, the planet’s travel at different speeds at different positions in the orbit. • _____________ • The planet’s position in it’s orbit where it is _________to the Sun. • The speed is __________ at perihelion Perihelion closest fastest

38. This means that because the orbits are elliptical, the planet’s travel at different speeds at different positions in the orbit. (2) _____________ • The planet’s position in it’s orbit where it is _________ from the Sun. • The speed is __________ at aphelion Aphelion farthest slowest

39. Earth’s Orbit

40. Kepler’s Third Law of Planetary Motion(Called the Harmonic Law) period of revolution • The time it takes the planet to revolve around the sun (it’s _____________________) is equal to the cube it its distance from the Sun. The period (P) must be in Earth years and the distance (D) must be in astronomical units. The equation can be stated: P2 = D3. • This further states that _______________________________________ • _________________________________________________________ farther a planet is from the Sun, the longer it takes to make one complete revolution

41. C. Celestial Mechanics Affecting Planetary Motions 1. The Laws of Sir Isaac Newton (1642-1727)

42. a. Newton’s First Law • Every body continues in it’s state of rest, or of uniform motion unless____________________________. • An object ___________ at rest or _____________ to move in direction and velocity. • Law of __________. external force is applied to it remains continues Inertia

43. 2. Newton’s Universal Law of Gravitation Inverse Square Law • Referred to as the ______________________. • The force of attraction between two bodies is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers. • Expressed mathematically as: m1 m2 d2 F G F= force between the objects m1 and m2 = mass of object 1 and object 2 D = distance between the objects’ centers of mass G = gravitational constant (6.67 X 1011 N ∙ meter2/kg2) A Newton (N) is the force necessary to accelerate a 1 kilogram mass one meter/sec2

44. IV. Earth Motions: Rotation vs. Revolution

45. Rotation A. ____________ • Earth spins on it’s _________, the imaginary straight line through Earth between the North Pole and the South Pole • The axis of rotation is ________________ 23 ½ degrees from a perpendicular to the plane of Earth’s orbit. axis inclined

46. The north axis always stays aimed towards the North Star (________). Polaris

47. 4. Rate of Earth’s Rotation • Earth makes one complete turn from ______ to _______ every _____________. • Angular Rate of Rotation: One complete rotation is equal to _______ degrees in 24 hours or _________. west east 24 hours 360 15o/hr

48. c. Linear Rate of Rotation • Speed changes with __________ north or south of the equator. • The greater the latitude, the __________ the speed. • At the equator the speed is 1,000 miles/hour or 1,650 km/hour. latitude faster

49. 5. Evidence of Earth’s Rotation

50. a. The Foucault Pendulum (pronounced foo-koe) • Jean-Bernard Foucault • Suspended a 28 kg mass from a wire 67 m long from the dome of the Pantheon in Paris • 1851