A jouney through the universe

free ebooks ==> www.ebook777.com www.ebook777.com free ebooks ==> www.ebook777.com free ebooks ==> www.ebook777.com A Journey through the Universe Providing an in-depth understanding for both general readers and astronomy enthusiasts, this highly comprehensive book provides an up-to-date survey of our knowledge of the Universe The book explores our Solar System, its planets and other bodies; examines the Sun and how it and other stars evolve through their lifetimes; discusses the search for planets beyond our Solar System and how we might detect life on them; and highlights interesting objects found within our Galaxy, the Milky Way It also looks at our current understanding of the origin and evolution of the Universe, as well as many other intriguing topics, such as time, black holes and Einstein’s theories, dark matter, dark energy and the Cosmic Microwave Background The book is uniquely supported by video lectures given by the author, available online It also includes the very latest astronomical observations, such as those made by the Planck and Kepler spacecraft IAN MORISON spent his professional career as a radio astronomer at the Jodrell Bank Observatory, and he has had an asteroid named in his honour in recognition of his work In 2007 he was appointed Professor of Astronomy at Gresham College, the oldest chair of astronomy in the world He writes a monthly online sky guide and audio podcast for the Jodrell Bank Observatory and is the author of numerous articles for the astronomical press and of a university astronomy textbook His most recent book is An Amateur’s Guide to Observing and Imaging the Heavens (Cambridge University Press, 2014) www.ebook777.com free ebooks ==> www.ebook777.com free ebooks ==> www.ebook777.com A Journey through the Universe Gresham Lectures on Astronomy Ian Morison University of Manchester and Gresham College www.ebook777.com free ebooks ==> www.ebook777.com University Printing House, Cambridge CB2 8BS, United Kingdom Cambridge University Press is part of the University of Cambridge It furthers the University’s mission by disseminating knowledge in the pursuit of education, learning and research at the highest international levels of excellence www.cambridge.org Information on this title: www.cambridge.org/9781107073463 © I Morison 2015 This publication is in copyright Subject to statutory exception and to the provisions of relevant collective licensing agreements, no reproduction of any part may take place without the written permission of Cambridge University Press First published 2015 Printed in the United Kingdom by TJ International Ltd Padstow, Cornwall A catalogue record for this publication is available from the British Library Library of Congress Cataloguing in Publication data Morison, Ian, 1943– author [Lectures Selections] A journey through the universe : Gresham lectures on astronomy / Ian Morison, University of Manchester and Gresham College pages cm ISBN 978-1-107-07346-3 (hardback) Astronomy I Title QB51.M77 2015 520–dc23 2014016830 ISBN 978-1-107-07346-3 Hardback Additional resources for this publication at www.cambridge.org/9781107073463 Cambridge University Press has no responsibility for the persistence or accuracy of URLs for external or third-party internet websites referred to in this publication, and does not guarantee that any content on such websites is, or will remain, accurate or appropriate free ebooks ==> www.ebook777.com This book is dedicated to my friends and colleagues at Gresham College, the Mercers’ Company and the City of London Corporation, who have made my years associated with the College the most rewarding of my life www.ebook777.com free ebooks ==> www.ebook777.com free ebooks ==> www.ebook777.com Contents Preface page ix Acknowledgements xi Watchers of the skies Our Sun 12 Aspects of our Solar System The rocky planets 26 38 The hunt for Planet X 57 Voyages to the outer planets 70 Harbingers of doom Impact! 91 100 Four hundred years of the telescope 118 10 The family of stars 133 11 Aging stars 145 12 The search for other worlds 164 13 Are we alone? The search for life beyond the Earth 14 Our island Universe 179 192 vii www.ebook777.com free ebooks ==> www.ebook777.com viii Contents 15 Wonders of the southern sky 16 Proving Einstein right 209 226 17 Black holes: no need to be afraid 18 It’s about time 239 255 19 Hubble’s heritage: the astronomer and the telescope that honours his name 267 20 The violent Universe 285 21 The invisible Universe: dark matter and dark energy 22 The afterglow of creation 320 23 To infinity and beyond: a view of the cosmos Index 336 347 The colour plates can be found between pages 212 and 213 301 free ebooks ==> www.ebook777.com 342 A Journey through the Universe why should this be so? As eloquently described in the book Just Six Numbers by Professor Martin Rees (now Lord Rees), there are a number of parameters that have a major influence on how universes can evolve and how stars produce elements that are needed for life One of these has already been covered in this chapter: the constant Omega If Ω had been higher the Universe would have rapidly collapsed without allowing life a chance to evolve; if it had been smaller, galaxies and stars would not have formed In addition, if the cosmological constant, Λ (which is surprisingly small), had been larger, it would have prevented stars and galaxies forming You have also read in Chapter 22 how the galaxies formed as a result of fluctuations in the density of the primeval Universe – the so-called ‘ripples’ that are observed in the Cosmic Microwave Background The parameter that defines the amplitude of the ripples has a value of ~10−5 If this parameter were smaller the condensations of dark matter that took place soon after the Big Bang (and were crucial to the formation of the galaxies) would have been both smaller and more spread out, resulting in rather diffuse galaxy structures in which star formation would be very inefficient and planetary systems could not have formed If the parameter had been less than 10−6, galaxies would not have formed at all! But if this parameter were greater than 10−5 the scale of the ‘ripples’ would be greater and giant structures, far greater in scale than galaxies, would form and then collapse into super-massive black holes – a violent universe with no place for life! One parameter of our Universe is so well known that it is barely given a moment’s thought – the number of spatial dimensions, three But if this were either two (no complex structures) or four (forces fall as the inverse cube and atoms could not form), life could not exist Einstein’s famous equation, E = mc2, relates the amount of energy that can be extracted from a given amount of mass, so the value of c is obviously fundamentally important In practice only a small part of the energy bound up in matter can be released, as in the conversion of hydrogen to helium This process releases 0.7% of the mass of the four protons that form helium – a percentage closely linked to the strength of the strong nuclear force This parameter, 0.007, has been called ‘nuclear efficiency’ However, if this value were too small, say 0.006, the sequence of reactions that build up helium could not take place In the first of these reactions, two protons form a deuterium nucleus but, given a value of 0.006 for the nuclear efficiency, deuterium would be unstable so preventing the further reactions that give rise to helium – stars would be inert On the other hand, if this parameter were 0.008, meaning that nuclear forces were stronger relative to electrostatic forces, the electrostatic repulsion of two protons would be overcome and they could bind together so free ebooks ==> www.ebook777.com To infinity and beyond: a view of the cosmos no hydrogen would have remained to fuel the stars A critical reaction in the evolution of stars is the formation of carbon in the triple alpha process As described earlier, Fred Hoyle played a key role in the understanding of this reaction and pointed out that even a change of a small percentage from the observed value of 0.007 would have severe consequences on the amount of carbon that would be formed in stars – with obvious consequences for life as we understand it A ‘multiverse’ So how can it be that all the parameters described above are finely tuned so that we can exist? There are two possible reasons The first is that our Universe was ‘designed’ by its creator specifically so that it could contain intelligent beings, a view taken by some scientist-theologians A second view is that there are many universes each with different properties; the term ‘multiverse’ has been applied to this view We have no knowledge of what lies in the cosmos beyond the horizon of ‘our’ visible Universe Different regions could have different properties; these regions could be regarded as different universes within the overall cosmos Our part of the cosmos is, like baby bear’s porridge, just right String theory: another approach to a ‘multiverse’ Theoretical physicists have a fundamental problem Einstein’s General Theory of Relativity which relates to ‘gravity’ is a classical theory, whereas the other forces are described by quantum mechanics A ‘theory of everything’ has yet to be found that can bring together all the fundamental forces One approach that is being actively pursued is that of ‘string theory’ The early string theories envisioned a universe of ten dimensions, not four, making up a ten-dimensional space-time The additional six beyond our three of space and one of time are compacted down into tiny regions of space of order 10−35 m in size and called strings These are the fundamental building blocks of matter Different ‘particles’ and their properties depend on the way these strings are vibrating – rather like the way a string of a violin can be excited into different modes of vibration to give harmonically related sounds As these strings move they warp the space-time surrounding them in precisely the way predicted by general relativity So string theory unifies the quantum theory of particles and general relativity In recent years five string theories have been developed, each with differing properties In one there can be open strings (a strand with two ends) as well as www.ebook777.com 343 free ebooks ==> www.ebook777.com 344 A Journey through the Universe closed strings where the ends meet to form a ring The remaining four only have closed rings More recently, Ed Witten and Paul Townsend have produced an eleven-dimensional ‘M-theory’, which brings together the five competing string theories into a coherent whole This eleventh dimension (and it not impossible that there could be more) gives a further way of thinking about a multiverse We can think of a simple analogy: take three slices of bread and suspend them (perhaps with a knitting needle) with each slice separated by, say, three centimetres On the same side of each of these slices place some ants The ants could survive, at least for a while, by eating the bread of what is effectively a twodimensional universe To them the existence of other colonies of ants on adjacent slices would be unobservable If they could think, they would believe that they existed in a single two-dimensional universe But we can see that all of these exist within a cosmos that actually has a third dimension In just the same way, rather than being individual regions of one large spatially linked cosmos, it could be that other ‘universes’ exist in their own space-time – hidden from ours within a further dimension Beyond our imagination In the description of the final talk that I gave as Gresham Professor of Astronomy, I ended with: ‘ or even that our Universe could just be one small part of a multiverse that extends beyond our imagination!’ I was implying that the totality of the cosmos and the laws that govern its existence might well be beyond the ability of our human minds to grasp (Certainly mine!) I was interested to read comments made later that year by Lord Rees, Astronomer Royal, past president of the Royal Society and previous holder of the Gresham Chair of Astronomy:  Some of the greatest mysteries of the Universe may never be resolved   because they are beyond human comprehension Rees suggests that the inherent intellectual limitations of humanity mean we may never resolve questions such as the existence of parallel universes, the cause of the Big Bang, or the nature of our own consciousness He even compares humanity to fish, which swim through the oceans without any idea of the properties of the water in which they spend their lives ‘A ‘true’ fundamental theory of the Universe may exist but could be just too hard for human brains to grasp Perhaps I am not alone! free ebooks ==> www.ebook777.com To infinity and beyond: a view of the cosmos The future of the Universe The accelerating expansion of the Universe that is now accepted has a very interesting consequence It used to be thought that, with a slowing rate of expansion, as the Universe became older we would see an increasing number of galaxies (as the distance we could see becomes greater) In a universe whose expansion is accelerating the exact opposite will be true – yes, we will be able to see further out into space, but there will be increasingly less and less for us to see as the expansion carries galaxies beyond our horizon On the large scale, the space between the galaxy clusters will be expanding – carrying them apart ever faster – but it is believed that clusters like our own Local Group will remain gravitationally bound and, in fact, its members will merge into one single galaxy largely made up from our own Milky Way Galaxy and the Andromeda Galaxy If one looks forwards in time to ~100 billion years, any observers in existence within this ‘galaxy’ would see a totally empty Universe! The expansion of space will have carried all other galaxies beyond our horizon – the edge of the visible Universe It would be virtually impossible for such observers to learn about the evolution of the Universe for a number of reasons, including the fact that the peak of the energy spectrum of the Cosmic Microwave Background (CMB) will have redshifted down to ~1 m and would be virtually impossible to detect From theoretical studies of stellar evolution and how the relative abundances of the elements change with time (for example, the amount of hydrogen is reducing and that of helium increasing as a result of nucleosynthesis in stars) it might well be possible to estimate the age of the galaxy, but it would be not be possible to infer that its origin involved a Big Bang We happen to live at the only time in the history of the Universe when the magnitude of dark energy and dark matter are comparable and also when the CMB is easily observable, so enabling us to infer the existence of dark energy and the way in which the Universe has evolved since the Big Bang, and to postulate its future runaway expansion Any observers present when the Universe was young would not have been able to infer the presence of dark energy as, at that time, it would have had virtually no effect on the expansion rate Those in the far future will not be able to tell that they live in an expanding universe at all, and not be able to infer the existence of dark energy either As the longest lived stars come to the end of their lives, the evidence that lies at the heart of our current understanding of the origin and evolution of the Universe will have disappeared www.ebook777.com 345 free ebooks ==> www.ebook777.com 346 A Journey through the Universe Now is about the best time in the life of the Universe to unravel its mysteries Thank you for joining with me in this quest More in-depth reading: Just Six Numbers by Martin Rees (Phoenix) The Elegant Universe by Brian Greene (Vintage) Cosmology by Steven Weinberg (Oxford University Press) free ebooks ==> www.ebook777.com Index 2003 UB313, 26 Bayer, Johann, 212 3C 273, 125 Bell Telephone Laboratories, 75-metre Mark I radio 322 telescope, 247 active galaxies, 246 NGC 4261, 248 gravitational microlensing, 243 Hawking radiation, 252 Bell, Jocelyn, 159, 161 Hawking temperature, 253 Belville, Ruth, 264 intermediate mass, 240 Bessel, Friedrich, 121, 151 Kerr black holes, 242 Bethe, Hans, 146, 321 Monoceros X-1, 245 Adams, John Couch, 60, 77 Bevis, John, 154 neutron degeneracy Airy, George, 60 Big Bang theory, 294 albedo, 33 Earth, 33 Enceladus, 63 no-hair theorem, 241 flat or critical universe, Omega Centauri, 240 337 Mars, 33 flatness problem, 296 Mercury and Moon, 63 Friedmann models, 338 Venus, 33, 63 Heisenberg’s uncertainty Alpher, Ralph, 321 principle, 295 Alpher–Bethe–Gamow paper, 321 pressure, 240 closed universes, 337 Penrose process, 242 Schwarzschild radius, 240, 241 singularity, 240 size of emitting region, 249 horizon problem, 296 super-massive, 240 inflation, 295 what are they?, 239 anthropic principle, 148 initial singularity, 294 apehelion, 28 Omega, 337 Bode, Johann Elert, 55 zero energy content, 294 Bondi, Herman, 339 Apian, Peter, 94 X-ray binary systems, 244 astronomical unit, 10 binary pulsar, 233 Brahe, Tycho, 4, 91, 155 Aurora Australis, 21, 22 Birr Castle, 122 British eclipse expedition, 229 Aurora Borealis, 21, 22 black holes, 239 Brown, Mike, 28, 67 auroral corona, 23 A0620–00, 246 Burke, Bernie, 323 angular momentum, 241 Burney, Venetia, 62 Baade, Walter, 302, 338 Ariel IV, 245 Butler, Paul, 169 Backus, Peter, 191 Cygnus X-1, 245 Banks, John, 11 evaporation, 253 Campbell, Bruce, 169 Barringer, Daniel, 101 event horizon, 239, 241 Campbell, William, 229 347 www.ebook777.com free ebooks ==> www.ebook777.com 348 Index celestial sphere, coronal mass ejections, 22 Cepheid variables, 123 Cosmic Microwave Ceres, 26 Background, 252, Challis, James, 60 265, 296, 306, 321, Chandrasekhar, Subramanyan, 150 Cherenkov radiation, 17, 156 Chre´tien, Henri, 123 345 black body spectrum, 324 Boomerang balloon, 328, 330 Big Bang models, 336 closed universes, 337 flat or critical universe, 337 Friedmann models, 338 Omega, 337 Big Bang or Steady State, 339 consistent model, 341 Christy, James, 64, 89 cause, 323 continuous creation, 339 Clark, Alvan, 121, 151 cause of fluctuations, 326 cosmological principle, 339 Clarke, Arthur C., 113 COBE spacecraft, 324 cosmological redshift, 338 climate change, 32 CMB fluctuations, 325 flatness problem, 340 comets, 91 differential microwave Freidmann models, 340 1P/Halley, 92 antitail, 95 radiometer, 324 far-infrared absolute future of the Universe, 345 horizon problem, 340 Bayeaux Tapestry, 92 spectrophotometer, Hubble’s constant, 338 Borrelly, 95 324 inflation, 340 coma, 94, 95 comet of 1577, 91 Deep Impact Mission, 98 dust tail, 94 mapping anisotropies, 324 Cosmic Background Imager, 329 gas or ion tail, 94 Maxima balloon, 328 Giotto image, 95 Planck mission, 329 Giotto space probe, 95 Planck results, 329 multiverse, 343 perfect cosmological principle, 339 Steady State theory, 336, 339 string theory, 343 M-theory, 344 Universe fit for life, 341 great comets, 95 age of Universe, 332 Crab Nebula, Hale–Bopp, 91 components making up Currie, Thayne, 166 Halley’s, 92 Universe, 331 Holmes, 95 curvature of space, 329 d’Arrest, Heinrich, 60 icy conglomerate theory, 94 Hubble’s constant, 333 dark energy, 315 ion tail, 95 reionisation redshift, 332 Casimir experiment, 318 Kuiper Belt, 93 Planck spacecraft, 327 evidence, 316 long-period, 92 serendipitous discovery, High-z Supernova Search nuclei, 92, 93 Oort Cloud, 93 Shoemaker–Levy 9, 65 322 Sunyaev–Zel’dovich effect, 329 Team, 317 Hubble plot, 317 Lambda (Λ) term, 315 short-period, 93 Very Small Array, 329 nature of, 318 Stardust mission, 97 WMAP spacecraft, 327 standard model of Tempel 1, 98 water on Earth, 99 Wild 2, 97 CMB Power Spectrum Analyzer, 333 results, 328 constant of gravitation, cosmological constant, 336 Cook, Captain James, 11 cosmology, 336 Copernican model of the Solar System, beyond our ability to fully understand, 344 cosmology, 319 supernova cosmology project, 317 Type Ia supernova, 316 dark matter, 301 Abell Cluster 2218, 308 amount, 309 free ebooks ==> www.ebook777.com Index cold dark matter, 309 Alpha Magnetic Spectrometer, 311 AMANDA, IceCube and ANTARES, 311 Dusky Sound, 11 astrometry, 173 dwarf planets, 28, 68 COROT, 175 Ceres, 69 detection in infrared, 164 Eris, 68 detection in visible light, 165 Haumea, 69 Formalhaut b, 166 axions, 310 Makemake, 69 Gaia spacecraft, 174 CRESST experiment, 312 Pluto, 69 Gliese, 174 cryogenic detectors, 312 DAMA experiment, 312 gravitational microlensing, Earth, 29, 42 171 direct detection, 311 Cambrian era, 43 HD 209458b, 175 indirect detection central core, 44 Kepler, 175 Chicxulub crater, 43 Kepler Space Observatory, experiments, 310 LUX experiment, 313 equatorial bulge, 43 LUX first results, 314 mass extinctions, 43 OGLE-2005-BLG-390Lb, 172 LUX-ZEPLIN, 314 photosynthesis, 42 OGLE-TR-56b, 175 neutralino, 310 plate tectonics, 43 planetary transits, 174 PAMELA, 311 secondary atmosphere, 42 radial velocity method of percentage mass, 315 Earth–Moon system, 42 weakly interacting eclipses, 23 massive particles annular, 24 (WIMPs), 310 eclipse track, 24 176 detection, 167 visual detection, 164 Fermi Gamma-ray Space gas entrapment, 307 lunar, 23 gravitational lensing, 307 ring of fire, 24 Flagstaff Observatory, 51 hot dark matter, 309 saros, 25 Flamsteed, John, 60 solar, 24 Fowler, William, 148 neutrinos, 309 in galaxy M33, 304 Eddington, Arthur, 228 in spiral galaxies, 303 Einstein rings, 243 MACHO, 301 Einstein, Albert, 12, 17, 265, mass to light ratio, 306 role in galaxy formation, 306 what is it?, 309 Davis, Ray, 17, 313 315 Einstein’s General Theory of Friedmann, A A, 336 galaxies, see also Milky Way active galactic nucleus, 224 Andromeda Galaxy, 204 Relativity, 84, 226, Coma Cluster, 206 233 Coma Supercluster, 207 Einstein’s Special Theory of de Grasse Tyson, Neil, 27 Telescope, 311 Relativity, 156, 233 cosmic web, 208 distances, 207 de Lacaille, Nicolas Louis, epicycles, elliptical, 203 220, 221 Eris, 29, 30 groups of, 204 deferents, Essen, Louis, 261 Hercules Cluster, 206 di Bondone, Giotto, 92 European Southern Hubble sequence, 203 Dicke, Richard, 320, 321, 323 Dixon, Jeremiah, 10 Dolland, John, 120 Observatory, 130 European Space Agency, 275, 329 Double Pulsar, 235 Ewen, Harold, 198 Drake, Frank, 181, 184 exoplanets, 164 Duhalde, Oscar, 220 51 Pegasai, 169 Hubble Ultra Deep Field, 208 irregular, 204 Large Magellanic Cloud, 204, 219 supernova 1987A, 220 distance, 220 www.ebook777.com 349 free ebooks ==> www.ebook777.com 350 Index galaxies (cont.) Tarantula Nebula, 219 gravitational time dilation, 266 Hoyle, Fred, 147, 160, 320, 336, 339, 343 Local Group, 204 Giotto di Bondone, 92 Hubble age, 274 M33 in Triangulum, 205 Global Positioning System Hubble sequence, 274 Magellanic Clouds, 217 Omega Centauri, 212 intermediate-mass black hole, 213 realm of, 205 Sgr A*, 211 Small Magellanic Cloud, 204, 219 spiral, 204 superclusters, 207 super-massive black holes, 211 Virgo Cluster, 206 network, 233 global warming, 32 Gold, Thomas, 161, 339 Goodricke, John, 270 Gran Sasso National Laboratory, 312 Hubble Space Telescope Hubble Heritage Images, 284 Wide Field Camera 3, 278 Hubble Space Telescope science Grand Unified Theory, 155 Cepheid distance scale, 279 gravitational lenses, 230 dark matter and dark Double Quasar, 231 gravitational wave detectors, energy, 281 exoplanet atmospheres, 237 281 gravitational waves, exoplanets, 281 226, 235 eXtreme Deep Field, 283 Virgo Supercluster, 207 gravitons, 237 Whirlpool Galaxy, 204 Green, Charles, 11 white nebulae, 203 Guccione, Giuseppe, 180 gamma ray bursts, 281 Guth, Alan, 296, 340 Hubble’s constant, 273, 279 Galilei, Galileo, 1, 59, 118, 259 Galle, Johann, 60 gamma-ray bursts, 253, 285 galaxy formation and evolution, 282 Hubble Deep Field, 282 Hale, George Ellery, 124, 269 Hubble Ultra Deep Field, 283 afterglow, 289 Hall, George, 111 Pluto, Nix and Hydra, 280 black hole formation, 291 Halley, Edmond, 10, 91 Shoemaker–Levy 9, 280 causes, 287, 290 Harriot, Thomas, 118 Compton Gamma Ray Harvard College Observatory, Observatory, 286 270 supernova 1987A, 278 Hubble, Edwin, 121, 123, 203, 266, 267, 337 discovery, 285 Haumea, 28 an attorney, 268 discovery of GRB 970508, Haveaheart pigeon trap, 322 at University of Chicago, 267 Hawking, Stephen, 252, 254 cometary nebula, 268 energy, 289 287 Hayden Planetarium, 26 distance to Andromeda Gamma-Ray Burst Heisenberg’s uncertainty Coordinates Network, 288 principle, 252 Galaxy, 272 expanding universe, 273 Helmholtz, Hermann von, 12 galaxy classification, 274 GRB 090423, 288 Herman, Robert, 321 infantry, 269 GRB 970228, 287 Herschel, Caroline, 58 Legion of Merit, 270 long, 289, 291 Herschel, John William, 212, Mount Wilson Observatory, short, 288 Swift spacecraft, 288 Vela spacecraft, 285 223 Herschel, William, 57, 74, 89, 122, 151 269 Rhodes scholarship, 267 study for a PhD, 268 Gamow, George, 306, 320 Hewish, Antony, 159 Hubble’s constant, 266, 273 General Theory of Relativity, Homestake Mine, 17 Hubble’s law, 272 Horowitz, Paul, 182, 187 Hulse, Joseph, 233 240, 336 free ebooks ==> www.ebook777.com Index Huygens, Christiaan, 83, 85, 260 hydrogen Balmer series, 137 Great Red Spot, 81 closest approaches, 29 mass, 80 Curiosity rover, 53 ring system, 82 Gusev Crater, 52 Mariner 9, 53 ice dwarfs, 66 Kamioka Underground Ixion, 66 Observatory, 155 Varuna, 66 Kepler, Johannes, 5, 119, 155, impacts, 100 Asclepius, 107 asteroid 2004 FH, 107 Mariner spacecraft, 51 Mars Global Surveyor, 51 Mars Reconnaissance 176 Orbiter, 52 Kepler’s third law of Martian soil analysis, 54 planetary motion, Meridiani Planum, 52 asteroid 2008 TC3, 107 Klebasabel, Ray, 285 Olympus Mons, 51 Barringer Crater, 101 Kuiper Belt objects, 66, 281 permafrost, 53 Chelyabinsk meteor, 108 Kulik, Leonid, 106 Phobos and Deimos, 54 Chicxulub asteroid, 103 polar ice caps, 49 Chicxulub crater, 103 L2 Lagrangian point, 327 south pole, 49 Comet Encke, 106 Laplace, Pierre-Simon, 239 Spirit and Opportunity, 52 crater formation, 101 Large Hadron Collider, 237, surface temperature, 49 eyewitness report, 105 Great Daylight Fireball, 107 Hubble Space Telescope, 109 impact craters, 100 253 Las Campanas Observatory, 220 Laser Interferometer instruments on Galileo spacecraft, 110 Viking landers, 51 Mason, Charles, 10 Mather, John, 326 Mauna Kea, Hawaii, 129 Gravitational Wave Maxwell, James Clerk, 85 Observatory, 236 Mayor, Michel, 169 Meteor Crater, 101 Lassell, William, 61 McKellar, A., 321 Noărdlinger Ries crater, 102 laws of planetary motion, McMillan, Robert, 66 Shoemaker–Levy 9, 109 Le Verrier, Urbain, 60, 77 Me´chain, Pierre, 10 Steinheim crater, 102 Leavitt, Henrietta, 270 Mercury, 29, 30, 31, 38 Tunguska event, 104 Lemonnier, Pierre, 60 BepiColombo, 39 Tycho, 101 Levy, David, 109 ice near poles, 38 Lindblad, B., 201 Magnetospheric Orbiter, 39 International Astronomical Union, 27 Lippershey, Hans, 118 Mariner 10, 38 inverse square law, Lowell Observatory, 121, 271 observed by radar, 38 Island of Hven, Lowell, Percival, 51, 57, 62, Planetary Orbiter, 39 121 Jodrell Bank MERLIN array, 283 Jodrell Bank Observatory, 11, 96, 125, 235 Jupiter precession, 227 meridian, Magellan spacecraft, 30 MERLIN array, 162 Magellan, Ferdinand, 219 Messier, Charles, 9, 205 Makemake, 28 meteor showers, 95 atmosphere, 81 Marcy, Geoffrey, 169, 187 bolide, 96 clouds, 80 Mars, 29, 49 Leonids, 97 core, 80 atmosphere, 49 meteor storm, 97 Galilean moons, 82 axial tilt, 49 Orionids, 96 Europa, 83 Beagle II lander, 51 Perseids, 97 Io, 83 canali, 50 radiant, 96 www.ebook777.com 351 free ebooks ==> www.ebook777.com 352 Index Milgrom, Mordehai, 304 Orion Nebula, 195 Morrison, Philip, 180 Milky Way, 192 Orion Spur, 202 Mount Wilson Observatory, 21-cm line, 198 Perseus Arm, 201 central bar, 211 RR Lyrae stars, 196 Cepheid variables, 197 Scutum-Centaurus Arm, 201 constellation Carina, 215 Sgr A*, 202 1036 Ganymed, 112 size, shape and structure, 433 Eros, 112 Eta Carinae, 215 123, 269 near-Earth objects, 112 Eta Carinae Nebula, 215 196 Southern Pleiades, 215 spiral arms, 198 Don Quijote, 116 spiral structure, 201 extinct comets, 112 spiral structure puzzle, 200 Large Synoptic Survey constellation Centaurus, 211 Centaurus A, 223 constellation Crux, 214 super-massive black hole, Alpha Crucis, 214 Coal Sack, 215 Jewel Box, 214 constellation Tucanae 47 Tucanae, 221 millisecond pulsars, 222 search for planets, 221 constellation Vela, 217 202 visible constituent, 192 217 Telescope, 113 LINEAR programme, 112 NEAT, 113 Millikan, Robert, 267 Palermo scale, 114 minor planets, 55 Pan-STARRS, 114 Celestial Police, 55 Spaceguard, 113 Ceres, 55 Spacewatch, 113 main asteroid belt, 55 The Discovery Channel Titus–Bode law, 55 modified Newtonian Vela pulsar, 217 Vela supernova remnant, asteroids, 112 dynamics, 304 Moon craters Telescope, 114 Torino scale, 114 Near-Earth Objects, 66 Neptune, 29, 77 atmosphere, 77 dark nebula, 195 Copernicus, 47 cloud-top temperature, 77 disc, 193 Tycho, 47 diameter, 77 Eagle Nebula, 195 diameter, 44 discovery, 77 Galactic Centre, 192, 210 distance, 44 Great Black Spot, 77 galactic rotation curve, 198 gravitational pull, 44 ice giant, 77 globular clusters, 193 highlands, 45 mantle, 77 47 Tucanae, 194 libration, 44 mass, 77 M13 in Hercules, 194 exploration, 48 ring system, 78 Horsehead Nebula, 195 Apollo missions, 48 rotation period, 77 hydrogen line, 198 Jade Rabbit, 49 seen by Galileo, 77 hydrogen line profiles, 200 Luna 16, 20, and 24, 48 interstellar medium, 195 Lunar Orbiters, 48 neutral hydrogen (H I), 198 maria, 45 Triton, 78 neutron-degenerate matter, 241 obscuration by dust, 192 Mare Crisium, 46 Newton, Isaac, 7, 91, 122, 143 Omega Centauri, 194 Oceanus Procellarum, 45 Newton’s Law of Gravitation, open clusters, 192 Hyades and Pleiades clusters, 193 Perseus Double Cluster, 193 Moon illusion, 44 226 orbit, 47 regolith, 47 occultations of Pluto, 64 tidal force, 47 Opik–Oort cloud, 93 Moore Hall, Chester, 120 orbital inclination, 30 free ebooks ==> www.ebook777.com Index Palitzsch, Johann Georg, 91 secondary atmospheres, 35 rocky planets, 38 Palomar Observatory, 124 solar nebula, 33 Rømer, Ole Christensen, 82 Palomar Sky Survey, 126 Titan, 35 Roll, Peter, 321 Paranal Observatory, Triton, 35 Rosse, Third Earl of, 10, 122, 130, 211 Venus, 36 Paris Observatory, 60 volcanic eruptions, 35 Parkes Telescope in Australia, 235 planetary densities, 30 154, 204 Rubin, Vera, 303 Ryle, Martin, 340 planetary rotation periods, 31 parsec, 134 planetary temperatures, 31 Sagan, Carl, 78, 80 Parsons, William, 122 carbon dioxide, 32 Samuel Oschin Telescope, 66 Peach, Damian, 80 greenhouse effect, 32 Sanford Underground Penfield, Glen, 103 methane, 32 Research Facility, Penrose, Roger, 242 water vapour, 32 313 Penzias, Arno, 296, 322 Pluto, 26, 29, 30, 31 Saturn, 30 perihelion, 28 Charon, 64, 89 moons Perlmutter, Saul, 318 Kerberos and Styx, 65 Enceladus, 89 Petersen, Dan, 111 New Horizons, 65 Huygens Probe, 87 Phobos, 30 Nix and Hydra, 65, 89 lakes on Titan, 88 Piazzi, Giuseppe, 55 Pounds, Ken, 245 Pickersgill Harbour, 11 preons, 241 Pigafetta, Antonio, 219 primeval fireball, 322 Planet X, hunt for, 57 Mimas, 87 Titan, 85, 87 rings, 85 Princeton University, 323 A Ring, 86 discovery of Uranus, 58 proton–proton cycle, 13 Bright Ring, 86 Galileo recorded Neptune, Ptolemaic model of the Solar Cassini Division, 85 59 System, Uranus, 57 Purcell, Edward, 198 planetary atmospheres, 33 Crepe Ring, 86 Encke Division, 86 F Ring, 86 Eris, 35 quantum gravity, 240 evolution of Earth’s, 36 quantum mechanics, 237 Schiaparelli, Giovanni, 50 subduction, 36 quantum theory, 240 Schmidt, Bernhard, 125, 302 volcanic activity, 36 Roche limit, 86 quantum tunnelling, 13 Schmidt, Brian P., 318 Jupiter, 35 Quaoar, 28 Schmidt, Maarten, 125, 247 law of equipartition of quark-degenerate matter, 241 Scotti, James V., 109 quarks, 241 search for life beyond the energy, 34 Mars, 36 quasar, 247 Maxwell–Boltzmann 3C 273, 247 distribution, 34 Mercury, 35 Earth, 179 search for other worlds, 164 quasi-stellar objects, 125, 247 Sedna, 28 Queloz, Didier, 169 SETI, the Search for methane, 33 Extra-Terrestrial Moon, 35 radio galaxies, 246 nitrogen, 34 Rees, Martin, 342, 344 300-metre Arecibo dish, 72 Intelligence, 180 nitrous oxide, 33 relict radiation, 321 76-metre Lovell Radio oxygen, 34 Riess, Adam G., 318 Pluto, 35 Ritchey, George Willis, 123 Telescope, 72, 183 Allen Telescope Array, 189 www.ebook777.com 353 free ebooks ==> www.ebook777.com 354 Index SETI (cont.) Alpha Centauri AB, 211 surface temperature, 136 Arecibo dish, 182 apparent brightness, 133 triple alpha process (3α), Drake equation, 184, 186 black dwarf, 146, 152 evidence of other black holes, 162 Type Ia supernova, 280 carbon–nitrogen–oxygen Type II supernova, 154 civilisations, 188 Jodrell Bank, 183 Mark I radio telescope, 180 cycle, 146 Cepheid variables, 270, 279 optical SETI, 186 luminosity, 270 Project Ozma, 181 period–luminosity Project Phoenix, 72, 182, 183, 186 Project SERENDIP, 182 projects META and BETA, 182 relation, 270 Small Magellanic Cloud, 270 standard candle, 271 Chandrasekhar limit, 150 147 variable, 149 white dwarfs, 145, 149 Wolf–Rayet stars, 291 Stjerneborg, string theory, 237 Sun, 12 atmosphere chromosphere, 18 photosphere, 18 SETI Institute, 183 classification, 137 SETI@home, 183 colour, 136 convective zone, 15 Square Kilometre Array, Crab Nebula, 154, 158, 162 magnetic field, 19 Delta Cepheus, 270 Maunder minimum, 20 discovery of pulsars, 159 prominences, 21 Shapiro delay, 85, 232, 235 distances, 133 proton–proton cycle, 14, 16 Cassini spacecraft, 232 GAIA, 135 radiative zone, 15 Viking spacecraft, 232 Hipparcos, 135 rotation period, 19 191 Wow!, 181 Shapiro, Irwin A., 232 Shapley, Harlow, 197, 210, 271 Shelton, Ian, 220 Eta Carinae, 216, 292 hypernova, 217 Hertzsprung–Russell diagram, 139 solar corona, 18 solar neutrino problem, 16, 17 solar wind, 21 sunspot cycle, 20 Shoemaker, Carolyn, 109 high-mass, 152 sunspot pairs, 20 Shoemaker, Eugene M., 100, intrinsic brightness, 133 sunspots, 19, 20 108 lifetimes, 143 maximum, 20 Slipher, Vesto, 62, 121, 271 low-mass, 145 number, 20 Smoot, George, 326 luminosity, 133 penumbra, 19 solar maximum, 22 masses, 142 plage, 19, 20 Space Telescope Science neutron stars, 157, 235 Institute, 275 Special Theory of Relativity, 13, 226, 265 optical interferometry, 141 planetary nebula, 149 umbra, 19 super-massive black holes, 231, 246 proper motion, 135 galaxy M84, 249 Proxima Centauri, 212 mass, 249 Spitzer Space Telescope, 201 Sirius B, 151 Milky Way Galaxy, 250 Spitzer, Lyman, 274 size, 141 Sgr A*, 246 time dilation, 265 St John’s College, Cambridge, 60 direct measurement, 141 spectra, 137 Tautenburg Observatory, 126 spectroscopic parallax, 138 Taylor, Russell, 233 0.5 to ~8 solar masses, 146 stellar parallax, 133 telescopes aging, 145 supernova 1987A, 155 stars, 133 18.5-inch refractor, 121 free ebooks ==> www.ebook777.com Index achromatic doublet, 120 spun cast mirrors, 128 active optics, 127 Very Large Telescope, 130 adaptive optics, 127 Yerkes Observatory Airy pattern, 120 Telescope, 120 Alfred-Jensch-Telescope, 126 time, 255 atomic time, 257 Cassegrain, 123 caesium beam frequency eight-power, 118 standards, 257 Faulkes Telescopes, 131 Gemini North, 129 clocks Universal Time, 256 time line of the early Universe, 297 a note of caution, 300 dark matter begins to clump, 299 era of nucleosynthesis, 298 grand unification epoch, 297 atomic, 261 hadron epoch, 298 Gemini South, 129 caesium fountain, 262 inflationary period, 297 Hale Telescope, 200-inch, caesium beam, 261 lepton epoch, 298 hydrogen maser, 261 photon epoch, 299 NIST-F1, 262 Planck epoch, 297 124 Hooker Telescope, 100-inch, 123, 269 Hubble Space Telescope, 121, 275 COSTAR, 277 flawed mirror, 276 rubidium, 262 quark epoch, 298 Helio-chronometer, 258 Titius, Johann Daniel, 55 invar pendulum, 260 Tombaugh, Clyde, 62 long case or grandfather, Townes, Charles, 186 260 Townsend, Paul, 344 guidance system, 275 pendulum, 259 servicing missions, 275, quartz, 260 K31021A and K31021B, 67 quartz time standards, 261 K31021C, 67 Riefler pendulum, 260 Orcus, 67 Shortt free pendulum, 260 Sedna, 67 277 James Webb Space Telescope, 277 Keck Telescopes, 10-metre, 129 sundials, 258 water clocks, 258 Large Binocular Telescope, 129 Global Positioning System, reflecting telescope, 122 Multiple Mirror Telescope, 129 Xena, 68 Turner, Herbert Hall, 267 cosmic time, 265 Equation of Time, 256 Leviathan 72-inch trans-Neptunian objects, 66 257 Universal Law of Gravitation, Uraniborg, Greenwich Mean Time, 255 Uranometria, 212 leap second, 257 Uranus, 31, 75 Local Solar Time, 255 axial tilt, 75 Newtonian reflecting, 122 marine chronometers, 263 distance from the Sun, 75 optical interferometers, 130 pulsars, 264 mass, 75 Palomar 200-inch, 274 sidereal day, 257 moon Miranda, 76 Ritchey–Chre´tien, 123 sidereal time, 257 radiation belts, 76 robotic, 131 time transfer, 263 rings, 75, 76 Samuel Oschin Schmidt Telescope, 126 Belville family, 264 rotational period, 75 Greenwich Time Lady, Schmidt camera, 125 264 segmented mirrors, 129 simple, 120 radio-controlled clocks, 264 Spitzer Space Telescope, 274 time ball, 263 Venus, 29, 31, 40 Aphrodite Terra, 41 atmosphere, 42 farra, 42 www.ebook777.com 355 free ebooks ==> www.ebook777.com 356 Index gravitational ‘slingshot’, 73 Wesley, Anthony, 111 high albedo, 40 gravity assist, 73 Wheeler, John, 239 internal structure, 42 heliopause, 73 Whipple, Fred L., 94 Ishtar Terra, 41 New Horizons spacecraft, Whirlpool Galaxy, 122 Venus (cont.) Magellan spacecraft, 41 281 Wilkinson, David, 321, 327 Mariner spacecraft, 40 New Horizons mission, 89 Williams, Robert, 282 radar observations, 41 Pioneer 10, 70 Wilson, Robert, 296, 322 temperature, 40 Pioneer 10 plaque, 71 Witten, Ed, 344 transits, 40 Pioneer 11, 72 Woolsthorpe Manor, Veneras 7, and 10, 40 The Grand Tour, 73 violent universe, 285 Voyager 2, 74 VLBA array, 162 Neptune, 77 von Weizsaăcker, Carl, 146 Uranus, 75 voyages to the outer planets, 70 Voyagers and 2, 73 message, 78 asteroid belt, 70 Cassini–Huygens spacecraft, 84 Galileo spacecraft, 79 Yang, S., 169 Yerkes, Charles Tyson, 268 Zwicky, Fritz, 126, 302 Coma Cluster, 302 gravitational lenses, 302 Wales, William, 11 Schmidt camera, 302 Walker, G A H., 169 supernova, 302 Werthimer, Dan, 187 virial theorem, 303 ... poles and are known as the Aurora Borealis and Aurora Australis respectively (Aurora is the Roman goddess of the dawn, Boreas is the Greek name for the north wind, and Australis is the Latin word... star at the moment of transit The assistant is standing beside the clock at the lower right of the figure to measure the time at which the star transits and the scribe seated at a table at the. .. Mercury It has thus been possible to calculate the mass of all the Solar System planets and two of its dwarf planets Let us take Mars as an example Calculating the mass of Mars Mars has a satellite,