Chapter 5 part one.
- 1. he Great Galaxy in Andromeda - Credit & Copyright: John P. Gleason, Celestial Images ASTRONOMY EDUCATION & OUTREACH http://casswww.ucsd.edu/archive/public/astroed.html#TUTORIAL University of California, San Diego Center for Astrophysics & Space Sciences http://casswww.ucsd.edu/archive/public/tutorial/scale.html Space calendar http://www2.jpl.nasa.gov/calendar/ http://hubblesite.org/gallery/ album/solar_system/ http://solarsystem.nasa.gov/index.cfm http://solarsystem.nasa.gov/index.cfm
- 2. Chapter 5. The Solar System. Main points: 1-Overview of solar system: 2- Origin of the solar system. a- Planets. a- Solar nebula theory. b-Space debris. b- Extra- solar planets Sizes are to scale, but distances are not.
- 3. Chapter 5. The Solar System. Main points: If the sun were a large grapefruit (r~ 7 cm), the Earth would be a pinhead 15 meters away. Sizes are to scale, but distances are not.
- 4. Solar System Neptune Ur Three types of Asteroid an u s planets: Belt Sa t ur TERRESTRIAL Ju n JOVIAN pit Ma er AND rs Ea DWARF . Ve rth Me nu rcu s ry
- 5. Terrestrial Jovian Planets. Planets. Moon Uranus Jupiter Neptune Venus Mars Saturn Mercury Pluto Earth The Sun contains about 99.8% of the mass of the Solar System
- 6. July 17, 2009: Forty two years ago, Apollo astronauts set out on a daring adventure to explore the Moon. They ended up discovering their own planet.
- 7. Some general characteristics of the planets. Planets revolve around the sun, counterclockwise as seen from the north pole, in the same direction and almost in the same plane.
- 8. Mercury Venus Earth Earth Pluto Neptune Jupiter Saturn Uranus Comet
- 9. Mercury’s orbit is tipped 7o and Pluto’s 17.2o off the plane of the ecliptic or plane of the solar system.
- 10. Inclination of planets to the plane of the ecliptic. Terrestrial planets Venus rotates backwards
- 11. Inclination of planets to the plane of the ecliptic. Saturn 27 0 Jovian planets Uranus rotates on its side. •Sun’s axis is tipped 7o .
- 12. Of the following OBJECTS, the orbit of _______, is the most inclined with respect to the plane of the solar system. a- Venus b- Earth c- Mars d- Jupiter e- Pluto
- 13. The Terrestrial planets are inside the orbit of the asteroid belt.
- 14. Terrestrial planets and their moons. Counting from left to right Venus is the ______ object. a- first b- second c- third d- fourth
- 15. I am the planet _____ and the large scarf of about _____ km and _____ km deep, along the equator is called ________. My average surface temperature is only _______degrees.
- 16. I am the planet MARS and the large scarf of about 4 000 km and 200 km deep, along the equator is called Valles Marineris. My average surface Olympus V al temperature is only M on les M arin 210 K degrees. eris
- 17. Scientist believed that more than 4 billion years ago I had running water on my surface. Olympus V al M on les M arin If that is the case eris what went wrong with me and where is the water?
- 18. JOVIAN PLANETS Jupiter, Saturn, Uranus and Neptune.
- 19. Comparing Terrestrial and Jovian planets Terrestrial Jovian Earth has the Jupiter: 11 Earth’s radius. largest radius Saturn: 9 “ r = 6 380 km. Uranus: 4 “ Radius Neptune: 4 “
- 20. Comparing Terrestrial and Jovian planets Terrestrial Jovian Orbital Mercury 0.39 Jupiter: 5 radius in Venus 0.7 Saturn: 10 AU Earth 1 Mars 1.5 Uranus: 19 Neptune: 30 orbital Mer. 0.24 Jupiter 11.86 period Ven. 0.65 Saturn 29.542 (years) Earth 1 Uranus 83.75 Mars 1.88 Neptune 163.7 P2 = a3
- 21. Comparing Terrestrial and Jovian planets Terrestrial Jovian solid, rich in metals: Low % in metals and Fe, Al, Mg, Ni and silicates. silicates ( rocks). Composition Rich in gases , mostly hydrogen and helium. Low concentration of ices of water low melting materials Lots of ammonia (NH ), and 3 such us ices, water methane (CH4). and gasses Low concentrations of metals and silicates. Similar in composition to the sun. (Solar in composition)
- 22. Comparing Terrestrial and Jovian planets Terrestrial Jovian Hot molten core of silicate and metals Core: hot molten core of silicate (rocky core) and metals (rocky core) Structure Rocky mantle. Not defined Thin crust Not defined small atmosphere. large atmosphere.
- 23. Comparing Terrestrial and Jovian planets Terrestrial Jovian Density = High 3.9 to 5.4 Low 0.7 to 1.7 g/cm3 mass/volume g/cm3 Temperature From 273 to Cold atmospheres : 750 K less than 100 K Surface with numerous No surface. impact crates. Jupiter is 316 times the mass of the Earth and Saturn’s is 96. The rest of the planets together only have 33 Earth masses.
- 24. Mercury observed by Messenger, September 5, 2011
- 25. Comparing Terrestrial and Jovian planets Terrestrial Jovian Sidereal Mercury 58.64 days Jupiter 9.9 h Period of Venus Saturn 10.7 h rotation 243.18 days Uranus 17.2 h Earth 23.93 h Mars 24.62 h Neptune 16.1 h
- 26. Slow rotation Like the sun, the Jovian planets have Fast differential rotation rotation. Slow rotation
- 27. Comparing Terrestrial and Jovian planets Atmosphere Small or absent. Large Mercury lacks it. Terrestrial Jovian Ring No rings All have rings. The only rings visible from Earth are Saturn’s
- 28. Jupiter and Saturn have large internal pressure that converts hydrogen gas to the liquid metallic state, which is a good conductor of electricity. No boundary between liquid and gas. Jupiter Saturn Earth Hot molten core Metallic Liquid Hydrogen Atmosphere Atmosphere
- 29. Comparing Terrestrial and Jovian planets Terrestrial Jovian Moons Few or no moons Many moons. Mars has two small Some are larger than and Earth one. our moon. Mercury and Venus: Lots of smaller moons no moons.
- 30. The Jovian Largest planets have many moons. Some are bigger than our moon.
- 31. Moon Titan passing in front of Saturn NASA/JPLCaltech/SSI
- 32. Jupiter has 4 Galilean Moon: Io. Europa, Callisto and Ganymede and 12 smaller moons.
- 33. Jovians Uranus Neptune Jupiter Saturn
- 34. The Jovian planets a- are similar in composition to the sun’s. a- are similar in composition to the sun’s. b- are giant planets and thus, they have large densities. c- rotate very slowly. d- have cold cores, because they are far away from the sun. The presence or absence of atmosphere in planets or asteroids is related to the escape speed and surface temperature.
- 35. What is escape speed? The initial speed an objects needs to escape from the surface of a planet, star, moon or asteroid is the…….. Vo= 5 km/s Vo= 8 km/s Vo= 11.2 km/s mass Escape speed. VEscape = G radius
- 36. Celestial body Escape velocity (km/s) Moon 2.0 Mercury 4.0 Mars 5.0 Venus 10.0 Earth 11.2 Uranus 21.3 Neptune 23.5 Saturn 35.5 Jupiter 60 Sun 615 White Dwarfs 6 000 mass Neutron Stars 210 000 VEscape = G radius
- 37. If the atoms and molecules of a gas move with an average speed similar to the escape speed , that gas is not present in the planet’s atmosphere. Light molecules move faster than massive molecules, SO light molecules like hydrogen escape easily than the heavier ones, such as nitrogen or carbon monoxide.
- 38. Moon’s escape speed: 2 km/s Mercury’s escape speed: 4 km/s The Moon and Mercury practically do not have any atmosphere, because their surfaces get too hot and because they have low escape speed.
- 39. Recall: atoms and molecules move fast at high temperature and slow at low temperature. Therefore, a small planet (low escape speed) with high surface temperature does not have an atmosphere, but a small planet with low surface temperature might have an atmosphere.
- 40. Titan cold is cold (100 K) and has Mercury is hot and atmosphere ( 500 K) and does not have any atmosphere Mercury and Titan have similar volumes.
- 41. The Jovian planets are Jupiter’s cold and have a large escape speed: escape speed therefore, 60 km/s ~ 5 they have large Earth’s atmospheres.
- 42. The stars and most planets have Magnetic Fields. South Magnetic pole re phe t os gne Ma North Magnetic pole
- 43. The stars’ and planets’ magnetic field is due to the Dynamo Effect. Convection Rotation + of a Magnetic = field. conducting medium M here sp ag ne to - The Earth, the Jovian planets, the sun and stars have magnetic fields.
- 44. ct i on ve on . C ne The sun zo rotates very fast and has a large convection zone, thus its magnetic field is intense.
- 45. The Earth’s magnetosphere is the region where the magnetic field is felt. Magnetosphere
- 46. The “solar wind” consist of charged particles, protons and electrons escaping the sun’s upper atmosphere. Most of the particles in the solar wind are deflected by The charged particles from the sun interacts the Earth’s magnetosphere. A few particles spiral down with the air molecules producing the aurorae to the northern and southern latitudes forming the borealis or australis. “aurorae”
- 47. The charged particles in the solar wind interact with the air molecules producing the aurorae borealis or australis.
- 48. Dwarf planets. In 2006 the International Astronomical Union (IAU) created a new category of planets: Dwarf planets. Name Distance Period (Y) Location from sun (AU) Ceres 4.6 4.6 Asteroid belt Pluto 40 248 Kuiper belt Haumea 43 285 Kuiper belt Makemake 48 310 Kuiper belt Eris 68 557 Kuiper belt
- 49. Three Dwarf Planet.. Ceres Pluto. Eris 2 247 Km 3 330 km 1000 km In the In the Kuiper belt Asteroid belt
- 50. Most of the dwarf planets are in the Kuiper belt, a cold region, beyond the orbit of Neptune. Pluto Kuiper belt Eris
- 51. definitions: Icy Frozen water, gases and liquids such as: body: NH3 ammonia, CH4 methane, CO2 . Rocky A solid body rich in silicates, body: SiO2 and metals: Fe, Ni, Al, and Mg.
- 52. Space Debris: Meteorites Comets Asteroids Asteroids
- 53. Asteroids. Asteroids are the remains of the Mars ‘planetesimals” that built the planets ~ 1.5 AU 4.6 billion years ago! Where are the asteroids ? 1- Most in the asteroid belt, Trojan with orbits between 1.8 AU and 3.3 AU. 2- The Trojan asteroids, share the orbit Tr with Jupiter. oj an Jupiter 5.2 AU
- 54. The Apollo asteroids cross the Earth’s orbit. Many asteroids are in the Kuiper belt, beyond the orbit of Neptune Jupiter 5.2 AU
- 55. The asteroids, in the Kuiper belt, are large chunks of solid material, mainly icy, held by gravity.
- 56. There are basically Three types of Asteroids: C-type: carbonaceous, dark S-type: silicate (rocky) M-type: metallic; iron and nickel Low density ~ 1.3 g/cm3 and are not made of solid hard rock.
- 57. Asteroids observed by Galileo spacecraft in the asteroid belt.
- 58. Most asteroids, have irregular shapes, rotate on their axis and come in different sizes from large, to small (pebbles). The self-gravity of the asteroids is not enough to pull them into a spherical shape. About 100 000 have been identified so far. Ida rotating on its axis (HST).
- 59. Asteroid Vesta Vesta observed by Dawn spacecraft from a distance of about 3,200 miles (5,200 kilometers). on July 24, 2011. Vesta ~ 600 km is the largest.
- 60. The spacecraft NEAR Shoemaker landed on the asteroid 433 Eros on February 2001.
- 61. These objects are a- rocks from the moon b- dwarf planets c- asteroids d- meteorites
- 62. Some asteroids a- have been discovered orbiting Jupiter b- are similar in composition to Jupiter c- have running water on their surface d- have diameters of 2 000 miles. e- none of the above. e- none of the above.
- 63. Bayeaux Tapestry Norman Invasion of Comet of 1577 1066
- 65. A Parts of a comet near the sun B C A= B= C=
- 66. Nucleus of comet Hartley 2 taken by NASA's EPOXI mission http://solarsystem.nasa.gov/index.cfm
- 67. Nucleus Irregular fluffy (lots of voids) mixture of ices and pulverized rock (tiny particles). Ices: water, carbon dioxide, ammonia methane and others. Rock: mainly pulverized silicates. nucleus of comet Hale, as Diameter of nucleus: from 10 to 50 km seen by Giotto and a density of (0.1 to 0.25) g/cm3. spacecraft.
- 68. The tails are produced Tails by vaporizing ices and dust (rock) from the nucleus. Tail st Du ail T g as n or Io Comet West (1975))
- 69. Ion or gas tail consists of ionized gases. The CO+ ions scatters the blue light more efficiently than any other color and thus it looks blue Tail g as n or Io Comet West (1975)
- 70. The dust tail consist of tiny dusty particles. The dust reflects all the visible light from the sun and looks white. Tail st Du
- 71. Tails point away from the sun pushed by the solar wind and solar radiation pressure. Tails are ~ 150 x106 km long.
- 72. Coma A Neat Comet. Kitt Peak National Observatory Tenuous cloud of (C/2001 Q4 z) evaporated gas, (CO2, H , water, ammonia, etc) and dust with a diameter of more than 100 000 km surrounding the nucleus. Surrounding the coma is an invisible layer, or hydrogen envelope; the hydrogen may come Coma from water molecules.
- 73. The comets have long elliptical orbits, because they come from far away. Orbit of Comet Kohoutek, 1973- 1974. http://history.nasa.gov/SP- 4208/p391.htm
- 74. Oort cloud Long period comets (more than 200 years of reappearance) Sun come from the Oort cloud and short period- less The Kuiper Belt. than 200 years - comets come from the Kuiper belt. Ort Cloud
- 75. Dimensions of the U 5x10 5 A Oort cloud. AU Inner radius 10 4 10 000 AU. Sun External Planetary radius region 50 000 AU.
- 76. No direct evidence of the Oort cloud! Comets from the Oort cloud, come in any direction from the sky,
- 77. The Kuiper belt: region of icy planetesimals. Pluto, Charon, Triton, Quaoar, Sedna, Eris, and more.
- 78. Why do comets leave their In the Oort cloud homes? occasional passing stars may perturb the orbits. In the Kuiper belt collision between them, or the gravitational force of Jupiter.
- 79. A solar system object, of rocky composition and comparable in size to a small city is most likely. a- a meteor c- an asteroid b- comet c- an asteroid d- a planet e- a meteoroid.
- 80. Short period comets and origin of meteors. First Second Third Hundredth Orbit Orbit Orbit. Orbit . …… The nuclei of comets are fragile and lose lots of matter every time they come close to the sun leaving behind a trail of tiny particles.
- 81. Some definitions Meteoroid. Small solid particle moving towards earth’s atmosphere. Meteor. Trail of light. “Shooting star’. Meteorite. A particle that reaches earth’s surface. Many have been found.
- 82. Meteor Meteors and the meteor Showers. showers are produced when the Earth enters the trail of particles left behind by comets. The meteors captured by Earth increase its mass 200 tons per day. Meteors are related to comets!
- 83. Meteor showers, seem to come from the same place in space. The Leonid meteor shower, (November 14- 19), seems to come from the Leonid constellation.
- 84. 1997 Leonids from Orbit After midnight the speed of the meteors and the The 1833 storm rotation of the Earth's speed adds up improving the chance to see a meteor
- 85. Meteorites. Particles that reach earth’s surface are the Meteorites. Meteorites endure the high temperature caused by air’s friction . Meteorites appear to be fragments of asteroids and even of terrestrial planets. Iron-Ni, with ~ 7% Ni.
- 86. There are basically Three types of meteorites: C-type: carbonaceous, dark S-type: silicate (rocky) M-type: metallic; iron and nickel So: three types of asteroids. Fe
- 87. Meteorite from the surface of Mars. It was hurled into space by and impact.
- 88. Which of the following is most likely related to comets? a- asteroids b- meteorites c- meteors c- meteors d- dwarf planets e- a & d.
- 89. Age of Solar System . - All objects in the solar system were formed around the same time. - The age of the meteorites gives the age of the solar system. Radioactive dating, Go to. http://lectureonline.cl.msu.edu/~mmp/applist/decay/decay.htm
- 90. Radioactive sample In ten hours at t = 0 hours Half life time - 10 hours. daughter The age of rocks is found comparing the original amount of radioactive (unstable) atoms and daughter abundance.
- 91. Examples of half life. Parent Daughter Half life years 238 U 206 Pb 4.5 billion 40 K 40 Ca, 40Ar 1.3 billion 226 Rb 87 Sr 47 billion Half-life is the time in which half of the radioactive mass decays.
- 92. The meteorites and the rocks from the moon are about 4.6 billion years old. This is the age of the solar system. Most of the oldest rocks found on Earth are only about 3.9 to 4.1 years old. The oldest rocks have been destroyed because the Earth is very active.
- 94. Decay of In 3 billion “Nonex” years how many particles of Nonex have decayed? a. 150 b. 1050 c. 220 c. 1050 d. 1000 1200 - 150 = 1050
- 95. Summary: Meteors: come from comets they are fragile and easily burnt upon entering the atmosphere. Meteorites: come from asteroids or planets. They are hard and make it to Earth. Comets have highly elliptical orbits. Asteroids are solid with rocky composition (carbon, silicates and metals). Objects in the Kuiper belt are icy and very cold. The age of the solar system, about 4.9 billion years, is estimated from the age of the meteorites.