lesson about the discussion Planeta.pptx

PPT Planets

1. The Solar System: our corner of the Universe The colour photograph of Earthrise - taken by Apollo 8 astronaut, William A. Anders, December 24, 1968. It was actually taken with the moon on the right edge of the image

2. The Solar System For thousands of years ancient astronomers saw points of light that appeared to move among the stars. They called these ‘planets’, meaning ‘wanderers’, and named them after the Roman gods. If you look up at a clear night sky, you too will be able to see many of the planets that the ancient astronomers saw. You might also see an assortment of space junk and satellites that also move in the night sky.

3. Pythagoras a Greek scientist who lived in the sixth century BC suggested that the Earth was the centre of the universe Aristotle (384–322 BC), Hipparchus (died after 127 BC) and Ptolemy (127–145 AD) proposed more detailed models in which Earth was placed at the centre of the solar system This type of model is known as the geocentric (geo-earth) or Ptolemy model Theories of the solar system

4. Geocentric Model

5. Geocentric Model Science Focus 1: Coursebook

6. Another ancient Greek, Aristarchus (310–230 BC) questioned the geocentric model and proposed a model where the Earth and other planets revolved around the Sun This is known as a heliocentric model (helio = Sun) The geocentric model continued to be favored until the end of the fifteenth century In the 1530’s, Polish astronomer Nicolas Copernicus (1473–1543) agreed with Aristarchus Theories of the solar system

7. Heliocentric Model http://en.wikipedia.org/wiki/Image:Heliocentric.jpg

8. Heliocentric Model Science Focus 1: Coursebook

9. Galileo (1564–1642) was a strong supporter of Copernicus’s ideas, in 1609 he used a telescope for the first time to make detailed observations of the Moon and planets; his observations exposed errors in the geocentric model Tycho Brahe (1546–1601) didn’t support the heliocentric theory and took numerous detailed measurements of the positions of stars and planets in an attempt to improve the geocentric model Theories of the solar system

10. Using Brahe’s data, German astronomer Johannes Kepler (1571–1630) finally showed the heliocentric model was correct Theories of the solar system

11. The solar system The term ‘solar system’ takes its name from the object at the centre of it all—the Sun, also known as Sol The nine planets of the solar system, in order starting from closest to the Sun, are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto* (*now known as a dwarf planet) A mnemonic device to remember the order could be: M y V ery E legant M other J ust S erved U s N ine P izzas What is your mnemonic device?

12. The solar system The planets each orbit the Sun, rotating on their axes as they do so The time taken for a planet to spin once on its axis is called its day, and the time taken to orbit the Sun once is called its year All the planets have days and years of different lengths

13. How the planets move The four innermost planets are called terrestrial (meaning ‘Earth-like’) and orbit the Sun in almost circular orbits The larger outer planets—Jupiter, Saturn, Uranus and Neptune—are known as the gas giants (or Jovian planets), because their outer layers are composed of gases such as hydrogen and helium, and they move in elliptical or oval orbits All planets move in the same plane (a large imaginary flat surface) except for Pluto, whose orbit is tilted by about 17° compared to the other planets’ orbits

14. http://solarsystem.jpl.nasa.gov/multimedia/gallery/vis_orb.jpg

15. http://solarsystem.jpl.nasa.gov/multimedia/gallery/outer_orb.jpg

16. Sun Mythology The Sun God. Greeks Called it Hellos Mass 333 400 times the mass of the Earth Diameter 1 392 000 km (109 x Earth’s diameter) Gravity 28 times that on Earth Surface Temperature 6000°C (average). From 4500 to 2000000°C up to 15000000°C in the core. Period of rotation (day) Equator 26 Earth days, poles 37 Earth days Tilt of axis 122°

17. Mercury Mythology God of travel, commerce and thieves Mass 0.056 times that of Earth Moons None Diameter 4878 km ( = 0.38 x Earth’s diameter) Surface Similar to Earth’s moon Gravity 0.38 times that on Earth Surface Temperature –170°C to 430°C Period of rotation (day) 59 Earth days Tilt of axis 0° Distance from Sun 0.39 AU (58 million kilometres) Time to orbit Sun (year) 88 Earth days

18. MERCURY The innermost   planet   in the   Solar System. It is also the smallest, and its orbit is the most   eccentric   (that is, the least perfectly circular) of .the eight planets. named after the Roman   god   Mercury, the messenger to the gods . Its surface is heavily cratered and similar in appearance to   Earth’s moon, indicating that it has been geologically inactive for billions of years.

19. MERCURY Its axis has the smallest   tilt   of any of the Solar System's planets, but Mercury's   orbital eccentricity   is the largest. At   perihelion , the intensity of sunlight on Mercury's surface is more than twice the intensity at   apehelion .

20. MERCURY I mage of Mercury with three visible colors mapped to 1000 nm, 700 nm, and 430 nm wavelengths

21. Venus http://en.wikipedia.org/wiki/Image:Venus-real.jpg Mythology Goddess of love and beauty Mass 0.815 times that of Earth Moons None Diameter 12 103 km ( = 0.95 x Earth’s diameter) Surface Extensive cratering , volcanic activity. Gravity 0.9 times that on Earth Surface Temperature 460°C Period of rotation (day) 243 Earth days Tilt of axis 30° Distance from Sun 0.72 AU (108 million kilometres ) Time to orbit Sun (year) 225 Earth days

22. Venus the second   planet   from the   Sun , orbiting it every 224.7   Earth   days. named after the   Roman   goddess   of love and beauty. After the   Moon , it is the brightest natural object in the night sky, reaching an   apparent magnitude   of −4.6, bright enough to cast shadows.

23. Venus It reaches its maximum brightness shortly before sunrise or shortly after sunset, for which reason it has been referred to by ancient cultures as the Morning Star or Evening Star . Classified as a   terrestrial planet and is sometimes called Earth's "sister planet " owing to their similar size, gravity, and bulk composition.

24. Venus shrouded by an opaque layer of highly reflective clouds of   sulfuric acid , preventing its surface from being seen from space in   visible light. It has the densest   atmosphere   of the four terrestrial planets, consisting mostly of   carbon dioxide . The   atmospheric pressure   at the planet's surface is 92 times that of Earth's .

25. Venus Venus is by far the hottest planet in the   Solar System. Venus's surface is a dry deserts cape interspersed with slab-like rocks and periodically refreshed by   volcanism .

26. Venus

27. The VENUS transit (2004)

28. Earth Mythology Gaia—mother Earth Mass 1.0 times that of Earth (5 980 000 000 000 000 000 000 000 kg) Moons One (‘the Moon’) Diameter 12 756 km Surface Two-thirds water, one-third land Gravity 1.0 times that on Earth Surface Temperature average 22°C Period of rotation (day) 1 Earth day Tilt of axis 23.5° Distance from Sun 1 AU (150 million kilometres ) Time for light to reach Earth 8 minutes Time to orbit Sun (year) 365.25 Earth days

29. Earth The third   planet   from the   Sun, and the   densest   and fifth-largest of the eight planets in the   Solar System. It is also the largest of the Solar System's four terrestrial planets . It is sometimes referred to as the   world , the Blue Planet ,   or by its Latin name,   Terra . formed   approximately 4.54 billion years   ago, and   life appeared   on its surface within one billion years .

30. Estimates on how much longer the planet will be able to continue to support life range from 500 million years, to as long as   2.3 billion years. During one orbit around the sun, the Earth rotates about its own axis 366.26 times, creating 365.26   solar days , or one   sidereal year . Earth

31. The Earth's axis of rotation is   tilted 23.4° away from the   perpendicular   of its   orbital plane, producing seasonal variations on the planet's surface with a period of one   tropical year   (365.24 solar days). The Moon is Earth's only   natural satellite. It began orbiting the Earth about 4.53 billion years ago. Earth

32. The Moon's gravitational interaction with Earth stimulates ocean   tides, stabilizes the axial tilt, and gradually slows the planet's rotation. The home of millions of   species. The shape of the Earth approximates an oblate spheroid , a sphere flattened along the axis from pole to pole such that there is a bulge around the equator . Earth

33. " The Blue Marble " photograph of Earth, taken from   Apollo 17. Earth

34. Mars Mythology God of war Mass 0.107 times that of Earth Moons 2 ( Phobos —diameter 23 km, Deimos —diameter 10 km) Diameter 6794 km ( = 0.53 xEarth’s diameter) Surface Soft red soil containing iron oxide (rust). Cratered regions, large volcanoes, a large canyon and possible dried-up water channels. Gravity 0.376 times that on Earth Surface Temperature –120°C to 25°C Period of rotation (day) 1.03 Earth days Tilt of axis 25.2° Distance from Sun 1.52 AU (228 million kilometres) Time to orbit Sun (year) 687 Earth days Time to reach Mars 9 months

35. Mars The fourth   planet   from the   Sun   and the second smallest planet in the   Solar System. Named after the   Roman   god of war . It is often described as the " Red Planet ", as the   iron oxide   prevalent on its surface gives it a   reddish appearance .

36. Mars is a terrestrial planet   with a thin   atmosphere, having surface features reminiscent both of the impact craters   of the   Moon   and the volcanoes, valleys, deserts, and   polar ice caps   of Earth. The   rotational period   and seasonal cycles of Mars are likewise similar to those of Earth, as is the tilt that produces the seasons. Mars

37. The site of   Olympus Mons , the second highest known mountain within the Solar System (the tallest on a planet), and of   Valles Marineris , one of the largest canyons. It has two   moons,   Phobos   and   Deimos , which are small and irregularly shaped. These may be captured   asteroids , similar to   5261 Eureka , a   Martian trojan asteroid . Mars

38. Olympus Mons

39. Phobos   and   Deimos

40. Until the first successful flyby of Mars occurred in 1965 by   Mariner 4 , many speculated about the presence of liquid water on the planet's surface. This was based on observed periodic variations in light and dark patches, particularly in the polar   latitudes , which appeared to be seas and continents; long, dark   striations   were interpreted by some as irrigation channels for liquid water. Mars

41. The straight line features were later explained as optical illusions , though geological evidence gathered by unmanned missions suggests that Mars once had large-scale water coverage on its surface Mars

42. Mars is currently host to five functioning   spacecraft : three in orbit—the   Mars Odyssey , Mars Express , and   Mars Reconnaissance Orbiter ; and two on the surface — Mars Exploration Rover Opportunity   and the   Mars Science Laboratory   Curiosity . Mars

43. True-color view of Mars seen through   NASA's Hubble Space Telescope in 1999. Mars

44. Mars

45. Jupiter Mythology Ruler of the Gods Mass 318 times that of Earth Moons At least 28 moons and four rings, including the four largest moons: Io, Ganymede, Europa and Callisto . These are known as the ‘Galilean’ moons. Diameter 142 984 km ( = 11.21 x Earth’s diameter) Surface Liquid hydrogen Gravity 2.525 times that on Earth Surface Temperature Cloud top –150°C Period of rotation (day) 9 hours 55 minutes Tilt of axis 3.1° Distance from Sun 5.2 AU (778 million kilometres) Time to orbit Sun (year) 11.8 Earth years

46. Jupiter The fifth   planet   from the   Sun   and the   largest   planet in the   Solar System. It is a   gas giant   with   mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in the Solar System combined. Jupiter is classified as a gas giant along with   Saturn ,   Uranus and   Neptune . These four planets are sometimes referred to as the   Jovian   or outer planets .

47. When viewed from   Earth, Jupiter can reach an   apparent magnitude   of −2.94, making it on average the third-brightest object in the   night sky   after the   Moon and   Venus. Primarily composed of   hydrogen   with a quarter of its mass being   helium , although helium only comprises about a tenth of the number of molecules. Jupiter

48. It may also have a rocky core of heavier elements,   but like the other gas giants, Jupiter lacks a well-defined solid surface. Because of its rapid rotation, the planet's shape is that of an   oblate spheroid   (it possesses a slight but noticeable bulge around the equator). Jupiter

49. The outer atmosphere is visibly segregated into several bands at different latitudes, resulting in turbulence and storms along their interacting boundaries. A prominent result is the   Great Red Spot , a giant storm that is known to have existed since at least the 17th century when it was first seen by   telescope. Jupiter

50. Jupiter

51. Surrounding Jupiter is a faint   planetary ring   system and a powerful   magnetosphere. There are also at least 67 moons , including the four large moons called the   Galilean moons that were first discovered by   Galileo Galilei   in 1610.   Ganymede , the largest of these moons, has a diameter greater than that of the planet   Mercury. Jupiter

52. It has 67   natural satellites .   Of these, 51 are less than 10 kilometres in diameter and have only been discovered since 1975. The four largest moons, known as the " Galilean moons ", are Io , Europa , Ganymede and Callisto . Jupiter

53. The Galilean moons, compared to Earth's Moon Name Diameter Mass Orbital radius Orbital period km  % kg  % km  % days  % Io 3643 105 8.9×10 22 120 421,700 110 1.77 7 Europa 3122 90 4.8×10 22 65 671,034 175 3.55 13 Ganymede 5262 150 14.8×10 22 200 1,070,412 280 7.15 26 Callisto 4821 140 10.8×10 22 150 1,882,709 490 16.69 61

54. Io

55. Europa the possible ice-covered liquid ocean on the moon Europa.

56. Ganymede the largest of these moons, has a diameter greater than that of the planet Mercury .

57. Callisto

58. Saturn Mythology God of agriculture Mass 95.184 times that of Earth Moons At least 30 moons and rings in seven bands Diameter 120 536 km (= 9.45 x Earth’s diameter) Surface Liquid hydrogen Gravity 1.064 times that on Earth Surface Temperature –180°C Period of rotation (day) 10 hours 39 minutes Tilt of axis 26.7° Distance from Sun 9.6 AU (1400 million kilometres) Time to orbit Sun (year) 29.5 Earth years

59. Saturn The sixth   planet   from the   Sun   and the second largest planet in the   Solar System, after   Jupiter. Named after the   Roman   god Saturn, its   astronomical symbol   ( ♄ ) represents the god's   sickle . Saturn is a   gas giant   with an average radius about nine times that of Earth.

60. Saturn's interior is probably composed of a core of iron, nickel and rock (silicon and oxygen compounds), surrounded by a deep layer of metallic hydrogen , an intermediate layer of   liquid hydrogen   and   liquid helium   and an outer gaseous layer. Exhibits a pale yellow hue due to ammonia crystals in its upper atmosphere. Saturn

61. Saturn has a prominent   ring system   that consists of nine continuous main rings and three discontinuous arcs, composed mostly of ice particles with a smaller amount of rocky debris and   dust . With 62   known   moons   orbit the planet; 53 are officially named. This does not include the hundreds of " moonlets " within the rings. Saturn

62. TITAN , Saturn's largest and the Solar System's second largest moon, is larger than the planet   Mercury   and is the only moon in the Solar System to retain a substantial atmosphere. Saturn

63. Saturn

64. Titan Saturn's largest and the Solar System's second largest moon. It is larger than the planet Mercury

65. Uranus Mythology Father of Saturn Mass 14.54 times that of Earth Moons At least 21 moons and 11 rings Diameter 51 200 km (= 4.01 x Earth’s diameter) Surface Likely to be frozen hydrogen and helium Gravity 0.903 times that on Earth Surface Temperature –220°C Period of rotation (day) 17 hours 14 minutes Tilt of axis 98° Distance from Sun 19.2 AU (2875 million kilometres) Time to orbit Sun (year) 84 Earth years

66. Uranus The seventh   planet   from the   Sun. It has the third-largest planetary radius and fourth-largest planetary mass in the   Solar System. Uranus is similar in composition to Neptune , and both are of different chemical composition than the larger   gas giants Jupiter   and   Saturn . Astronomers sometimes place them in a separate category called " ice giants ".

67. Uranus's atmosphere, while similar to Jupiter's and Saturn's in its primary composition of   hydrogen   and   helium , contains more " ices " such as water,   ammonia , and methane , along with traces of   hydrocarbons . It is the coldest planetary atmosphere in the Solar System, with a minimum temperature of 49  K   (−224  °C ). Uranus

68. It has a complex, layered   cloud   structure, with water thought to make up the lowest clouds, and methane thought to make up the uppermost layer of clouds.   In contrast, the interior of Uranus is mainly composed of i ces and rock. Like the other   giant planets , Uranus has a   ring system , a   magnetosphere , and numerous   moons . Uranus

69. The Uranian system has a unique configuration among the planets because its   axis of rotation   is tilted sideways, nearly into the plane of its revolution about the Sun. Its north and south poles therefore lie where most other planets have their equators . The wind speeds on Uranus can reach 250 meters per second (900 km/h, 560 mph). Uranus

70. Uranus

71. Uranus

72. Neptune Mythology God of the sea Mass 17.15 times that of Earth Moons 8 moons and 5 rings Diameter 49 528 km ( = 3.88 x Earth’s diameter) Surface Frozen hydrogen and helium Gravity 1.135 times that on Earth Surface Temperature –220°C Period of rotation (day) 16 hours 7 minutes Tilt of axis 29.3° Distance from Sun 30.1 AU (4500 million kilometres) Time to orbit Sun (year) 165 Earth years

73. Neptune the eighth and farthest   planet   from the   Sun   in the   Solar System. It is the fourth-largest planet by diameter and the third-largest by mass. Neptune is 17 times the mass of   Earth   and is somewhat more massive than its near-twin   Uranus, which is 15 times the mass of Earth but not as dense.

74. Neptune was the first planet found by mathematical prediction rather than by   empirical observation . Neptune was subsequently observed on 23 September 1846 by   Johann Galle within a   degree   of the position predicted by   Urbain Le Verrier , and its largest moon,   Triton , was discovered shortly thereafter. Neptune

75. Triton Neptune’s largest moon.

76. Neptune has been visited by only one spacecraft,   Voyager 2 , which flew by the planet on 25 August 1989. Neptune

77. Neptune

78. Sun (star) Jupiter (planet) Saturn (planet) Uranus (planet) Neptune (planet) Earth (planet) Venus (planet) Mars (planet) Ganymede (moon of Jupiter) Titan (moon of Saturn) Mercury (planet) Callisto (moon of Jupiter) Io (moon of Jupiter) Moon (moon of Earth) List of Solar System’s Objects by size

79. Europa (moon of Jupiter) Triton (moon of Neptune) Titania (moon of Uranus) Rhea (moon of Saturn) Oberon (moon of Uranus) Iapetus (moon of Saturn) Umbriel (moon of Uranus) Ariel (moon of Uranus) Dione (moon of Saturn) Tethys (moon of Saturn) Vesta (asteroid) Enceladus (moon of Saturn) Miranda (moon of Uranus) Proteus (moon of Neptune) List of Solar System’s Objects by size

80. Mimas (moon of Saturn) Hyperion (moon of Saturn) Phoebe (moon of Saturn) Janus (moon of Saturn) Amalthea (moon of Jupiter) Epimetheus (moon of Saturn) Prometheus (moon of Saturn) List of Solar System’s Objects by size

81. T H A N K Y O U S O M U C H !