Free Astronomy Books

This is the updated list of astronomy books available for free download or online reading. These books and papers cover all the areas of astrophysics, cosmology, galactic and extragalactic astronomy, solar and stellar physics, celestial mechanics, planetary science, astrobiology, as well as some popular works. The books are made available free of charge to the reader by their authors or publishers. Here is a categorized directory of astronomy books. This page is updated daily.

1. Mathematical Theories of Planetary Motions
   Otto Dziobek | The Register Pub. Co., Published in 1892, 314 pages
2. Views of the Solar System
   Calvin J. Hamilton | , Published in 2008
3. Inflation and String Theory
   Daniel Baumann, Liam McAllister | arXiv, Published in 2014, 349 pages
4. The Foundations of Celestial Mechanics
   George W. Collins, II | Pachart Pub House, Published in 2004, 145 pages
5. An Introduction into the Theory of Cosmological Structure Formation
   Christian Knobel | arXiv, Published in 2012, 102 pages
6. Cosmology: Mankind's Grand Investigation
   Greg Bothun | Harcourt Brace College Publishers, Published in 1999, 129 pages
7. Mathematical Problems Of Radiative Equilibrium
   Eberhard Hopf | Cambridge University Press, Published in 1934, 123 pages
8. Large Scale Structure of the Universe
   Alison L. Coil | arXiv, Published in 2012, 43 pages
9. Lunar Orbiter Photographic Atlas of the Moon
   D.E. Hughes, J.K. Bowker | Lunar and Planetary Institute, Published in 1971
10. Radiative Gas Dynamics
    David Weinberg | Ohio State University, Published in 2007
11. Why CMB physics?
    Massimo Giovannini | arXiv, Published in 2007, 179 pages
12. String Cosmology
    James M. Cline | arXiv, Published in 2007, 47 pages
13. Introduction to Cosmology
    A. D. Dolgov | arXiv, Published in 2009, 58 pages
14. Pioneer Saturn Encounter
    | NASA, Published in 1979, 45 pages
15. Dense Matter in Compact Stars
    Andreas Schmitt | arXiv, Published in 2010, 146 pages
16. Man's Place in the Universe
    Alfred R. Wallace | Chapman and Hall, Published in 1904, 330 pages
17. Planetary Theory
    Ernest Brown, Clarence Shook | Cambridge University Press, Published in 1933, 323 pages
18. Practical Astronomy for Engineers
    Frederick Hanley Seares | Stephens, Published in 1909, 160 pages
19. Archaeology, Anthropology, and Interstellar Communication
    Douglas A. Vakoch | NASA, Published in 2014, 330 pages
20. The Geology of the Terrestrial Planets
    Michael H. Carr | NASA, Published in 1984, 322 pages
21. General Astronomy
    Harold Spencer Jones | Edward Arnold and Company, Published in 1924, 392 pages
22. Superstring Cosmology
    James E. Lidsey, David Wands, E. J. Copeland | arXiv, Published in 2000, 161 pages
23. Pioneers of Science
    Oliver Lodge | Macmillan and co, Published in 1905, 421 pages
24. Quantization in Astrophysics, Brownian Motion, and Supersymmetry
    F. Smarandache, V. Christianto | MathTiger, Published in 2007, 516 pages
25. Advanced Topics in Cosmology: A Pedagogical Introduction
    T. Padmanabhan | arXiv, Published in 2006, 40 pages
26. Gravitational Wave Experiments and Early Universe Cosmology
    Michele Maggiore | arXiv, Published in 2000, 100 pages
27. Hubble 25: A Quarter-Century of Discovery with the Hubble Space Telescope
    Dylan Steele (ed.) | NASA, Published in 2015, 78 pages
28. Astronomical Image and Data Analysis
    J.-L. Starck, F. Murtagh | Springer, Published in 2006, 335 pages
29. Astronomy of To-day
    Cecil Goodrich Julius Dolmage | Seeley and co., Published in 1910
30. Star-Gazer's Hand-Book
    Henry William Elson | Sturgis & Walton, Published in 1910, 72 pages
31. TASI Lectures: Introduction to Cosmology
    Mark Trodden, Sean M. Carroll | arXiv, Published in 2004, 82 pages
32. Oulu Space Physics Textbook
    Reijo Rasinkangas | University of Oulu, Published in 2008
33. The Galactic Habitable Zone I. Galactic Chemical Evolution
    G. Gonzalez, D. Brownlee, P. Ward | arXiv, Published in 2001, 57 pages
34. Mysteries of the Sun
    Ginger Butcher | NASA, Published in 2011, 20 pages
35. Chondrules and their Origins
    Elbert A. King | The Lunar and Planetary Institute, Published in 1983, 377 pages
36. The Solar Magnetic Field
    Sami Solanki, Bernd Inhester, Manfred Schussler | arXiv, Published in 2010, 83 pages
37. Inflationary Cosmology and Structure Formation
    J. A. Peacock | arXiv, Published in 1996, 77 pages
38. Lectures on Black Holes, Topological Strings and Quantum Attractors
    Boris Pioline | arXiv, Published in 2007, 103 pages
39. A Practical Introduction to Numerical Hydrodynamics
    Garrelt Mellema | Leiden University, Published in 2003, 124 pages
40. The Cosmological Constant
    Sean M. Carroll | arXiv, Published in 2000, 50 pages
41. Introduction to Non-Baryonic Dark Matter
    Paolo Gondolo | arXiv, Published in 2004, 51 pages
42. Handbook of Space Astronomy and Astrophysics
    Martin V. Zombeck | Cambridge University Press, Published in 2006, 780 pages
43. Techniques of Radio Astronomy
    T. L. Wilson | arXiv, Published in 2011, 47 pages
44. Frequently Asked Questions about Calendars
    Claus Tøndering | , Published in 2008, 65 pages
45. Observations of the High Redshift Universe
    Richard S. Ellis | arXiv, Published in 2007, 115 pages
46. The Story of Eclipses
    George F. Chambers | S. S. McClure Co., Published in 1909, 208 pages
47. To a Rocky Moon: A Geologist's History of Lunar Exploration
    Don E. Wilhelms | University of Arizona Press, Published in 1993, 524 pages
48. From Disks to Planets
    Andrew N. Youdin, Scott J. Kenyon | arXiv, Published in 2012, 70 pages
49. The Cosmic Web: Geometric Analysis
    Rien van de Weygaert, Willem Schaap | arXiv, Published in 2007, 129 pages
50. A Guide To The Constellations
    Samuel G. Barton | McGraw-Hill, Published in 1928, 96 pages
51. Planetary Rings
    Matthew S. Tiscareno | arXiv, Published in 2011, 82 pages
52. Astronomy Notes
    Nick Strobel | astronomynotes.com, Published in 2010
53. Cosmology and Astrophysics
    Juan Garcia-Bellido | arXiv.org, Published in 2005, 76 pages
54. Celestial Navigation, Elementary Astronomy, Piloting
    Arturo Chiesa, Raffaele Chiesa | Sky and Sea Software, Published in 2010
55. The Beginning and Evolution of the Universe
    Bharat Ratra, Michael S. Vogeley | arXiv, Published in 2008, 69 pages
56. Textbook on Practical Astronomy
    George Leonard Hosmer | Wiley, Published in 1910, 252 pages
57. Lecture Notes on High Energy Cosmic Rays
    M. Kachelriess | arXiv.org, Published in 2008, 82 pages
58. A practical guide to Basic Statistical Techniques for Data Analysis in Cosmology
    Licia Verde | arXiv, Published in 2008, 52 pages
59. The Fine-Tuning of the Universe for Intelligent Life
    Luke A. Barnes | arXiv, Published in 2011, 76 pages
60. Recent Developments in Gravitational Collapse and Spacetime Singularities
    Pankaj S. Joshi, Daniele Malafarina | arXiv, Published in 2012, 89 pages
61. Magnetic Fields, Strings and Cosmology
    Massimo Giovannini | arXiv, Published in 2006, 76 pages
62. Searching for Life Across Space and Time
    | The National Academies Press, Published in 2017, 133 pages
63. Hubble Space Telescope: Discoveries
    | NASA, Published in 2012, 128 pages
64. Photographs of Nebulae and Clusters
    James Edward Keeler | University of California Publications, Published in 1908
65. Solar System
    | Wikipedia, Published in 2012, 646 pages
66. Practical Astronomy
    George L. Hosmer | John Wiley and Sons Inc., Published in 1925, 314 pages
67. Sky Surveys
    S. G. Djorgovski, A.A. Mahabal, A.J. Drake, M.J. Graham, C. Donalek | arXiv, Published in 2012, 62 pages
68. Galaxy systems in the optical and infrared
    A. Biviano | arXiv, Published in 2008, 60 pages
69. Radiative Processes in High Energy Astrophysics
    Gabriele Ghisellini | arXiv, Published in 2012, 157 pages
70. Observing the Sky from 40N
    Roberto Mura | Wikibooks, Published in 2010, 86 pages
71. A Primer for Black Hole Quantum Physics
    R. Brout, S. Massar, R. Parentani, P. Spindel | arXiv, Published in 2007, 178 pages
72. Big Bang Nucleosynthesis and Physics Beyond the Standard Model
    Subir Sarkar | arXiv, Published in 1996, 156 pages
73. The Practical Astronomer
    Thomas Dick | Seeley, Burnside, and Seeley, Published in 1845, 588 pages
74. Ultrahigh Energy Cosmic Rays: Facts, Myths, and Legends
    Luis Alfredo Anchordoqui | arXiv, Published in 2011, 92 pages
75. Lunar Stratigraphy and Sedimentology
    John Lindsay | Elsevier, Published in 1976, 311 pages
76. Modified Gravity and Cosmology
    T. Clifton, P.G. Ferreira, A. Padilla, C. Skordis | arXiv, Published in 2012, 312 pages
77. Lectures on Astronomy, Astrophysics, and Cosmology
    Luis A. Anchordoqui | arXiv, Published in 2007, 41 pages
78. Neutrinos and the Stars
    Georg Raffelt | arXiv, Published in 2012, 83 pages
79. To See the Unseen: A History of Planetary Radar Astronomy
    Andrew J. Butrica | NASA History Division, Published in 1996, 301 pages
80. The Star Splitters: The High Energy Astronomy Observatories
    Wallace H. Tucker | NASA History Office, Published in 1984, 182 pages
81. Origin of the Moon
    W. K. Hartmann, R. J. Phillips, G. J. Taylor | Lunar and Planetary Institute, Published in 1986, 781 pages
82. The Birth And Death Of The Sun
    George Gamow | Dover Publications, Published in 1940, 256 pages
83. The Hubble Constant
    Neal Jackson | arXiv, Published in 2014, 48 pages
84. Voyage to Jupiter
    David Morrison, Jane Samz | NASA, Published in 1980, 218 pages
85. Applied Cosmography: A Pedagogical Review
    Yu. L. Bolotin, et al. | arXiv.org, Published in 2018, 66 pages
86. Primordial Magnetogenesis
    Alejandra Kandus, Kerstin E. Kunze, Christos G. Tsagas | arXiv, Published in 2011, 107 pages
87. A New Astronomy
    David Peck Todd | American Book Company, Published in 1906, 437 pages
88. Astronomy with an Opera-glass
    Garrett Putman Serviss | D. Appleton & co., Published in 1890, 154 pages
89. Observational Probes of Cosmic Acceleration
    David H. Weinberg, et al. | arXiv, Published in 2012, 253 pages
90. An Expanded View of the Universe
    | European Southern Observatory, Published in 2011, 54 pages
91. Cosmic Journey: A History of Scientific Cosmology
    N. S. Hetherington, W. P. McCray | American Institute of Physics, Published in 2009
92. Galaxies and the Expanding Universe
    James Schombert | University of Oregon, Published in 2008
93. The Birth and Death of Stars
    James Schombert | University of Oregon, Published in 2008
94. Cosmology for Particle Physicists
    U. A. Yajnik | arXiv, Published in 2008, 63 pages
95. From Cosmic Birth to Living Earths: The Future of UVOIR Space Astronomy
    Julianne Dalcanton, et al. | arXiv, Published in 2015, 176 pages
96. The Astronomy of the Bible
    E. Walter Maunder | Richard Clay & Sons, Published in 1908
97. Guidebook to the Geology of Barringer Meteorite Crater, Arizona
    David A. Kring | Lunar and Planetary Institute, Published in 2007, 154 pages
98. Vision and Voyages for Planetary Science in the Decade 2013-2022
    | National Academy of Sciences, Published in 2011, 410 pages
99. Particle Physics and Inflationary Cosmology
    Andrei Linde | arXiv, Published in 2005, 270 pages
100. Voyager Encounters Jupiter
     | National Aeronautics and Space Administration, Published in 1979, 48 pages
101. Supernovae
     | Wikipedia, Published in 2014
102. An introductory treatise on the lunar theory
     Ernest W Brown | Cambridge University Press, Published in 1896, 312 pages
103. Cosmos and Culture: Cultural Evolution in a Cosmic Context
     Steven J. Dick, Mark L. Lupisella | NASA, Published in 2010, 612 pages
104. Atomic and Molecular Processes in Astronomy and Planetary Science
     Geoffrey A. Blake | California Institute of Technology, Published in 2004
105. Supernova Remnants: The X-ray Perspective
     Jacco Vink | arXiv, Published in 2011, 78 pages
106. Evolution of the Solar System
     Hannes Alfven, Gustaf Arrhenius | NASA, Published in 1976
107. Multi-messenger Astronomy and Dark Matter
     Las Bergstrom | arXiv, Published in 2012, 105 pages
108. Lecture notes on the formation and early evolution of planetary systems
     Philip J. Armitage | arXiv, Published in 2010, 63 pages
109. Introduction to Physical Astronomy
     Kenneth R. Koehler | University of Cincinnati, Published in 2010
110. Consolidated Lunar Atlas
     Gerald P. Kuiper, et al. | Lunar and Planetary Institute, Published in 1960
111. Gravitational Waves: Sources, Detectors and Searches
     Keith Riles | arXiv, Published in 2012, 79 pages
112. Astronomical Discovery
     Herbert Hall Turner | E. Arnold, Published in 1904, 225 pages
113. Elementary Astronomy
     James N. Pierce | , Published in 2013, 134 pages
114. Amateur Telescope Making
     | Springfield Telescope Makers Inc, Published in 2018, 428 pages
115. Introduction to Supersymmetry: Astrophysical and Phenomenological Constraints
     Keith A. Olive | arXiv, Published in 1999, 67 pages
116. Stellar Superfluids
     Dany Page, et al. | arXiv, Published in 2013, 88 pages
117. Recreations in Astronomy
     Henry White Warren | Project Gutenberg,
118. An Introduction to Galactic Chemical Evolution
     Nikos Prantzos | arXiv, Published in 2007, 46 pages
119. An Introduction to Cosmic Rays and Gamma-Ray Bursts
     A. De Rujula | arXiv, Published in 2007, 37 pages
120. Moon Trip: A Personal Account of the Apollo Program and its Science
     Elbert A. King | Lunar and Planetary Institute, Published in 1989, 162 pages
121. Protoplanetary Disks and Their Evolution
     Jonathan P. Williams, Lucas A. Cieza | arXiv, Published in 2011, 65 pages
122. An Introduction to Astronomy
     Forest Ray Moulton | The MacMillan Company, Published in 1916, 577 pages
123. First Light
     Abraham Loeb | arXiv, Published in 2006, 157 pages
124. Dark Energy: Observational Evidence and Theoretical Models
     B. Novosyadlyj, V. Pelykh, Yu. Shtanov, A. Zhuk | Akademperiodyka, Published in 2013, 380 pages
125. The Virial Theorem in Stellar Astrophysics
     George W. Collins, II | Pachart Pub. House, Published in 1978, 135 pages
126. Cosmology Primer
     Sean Carroll | preposterousuniverse.com, Published in 2012, 120 pages
127. Cosmological Evolution of Galaxies
     Isaac Shlosman | arXiv, Published in 2012, 88 pages
128. Astrochemistry: The Issue of Molecular Complexity in Astrophysical Environments
     M. De Becker | arXiv, Published in 2013, 62 pages
129. Cosmology
     James Schombert | University of Oregon, Published in 2008
130. Hours With A Three-Inch Telescope
     William Noble | Longmans, Green & Co., Published in 1887, 159 pages
131. The Universe in a Helium Droplet
     Grigory E. Volovik | Oxford University Press, Published in 2003, 532 pages
132. The History of Astrometry
     Michael Perryman | arXiv, Published in 2012, 52 pages
133. General Astronomy
     | Wikibooks, Published in 2009
134. Primer Of Celestial Navigation
     John Favill | Cornell Maritime Press, Published in 1944, 300 pages
135. Cluster Lenses
     Jean-Paul Kneib, Priyamvada Natarajan | arXiv, Published in 2012, 120 pages
136. Stellar Atmospheres
     J. B. Tatum | , Published in 2006
137. Observatories in Space
     Catherine Turon | arXiv, Published in 2011, 50 pages
138. The Shape of the Universe
     Gerd Pommerenke | viXra, Published in 2013, 321 pages
139. Caldwell Catalogue
     | Wikipedia, Published in 2014
140. Basaltic Volcanism on the Terrestrial Planets
     | Pergamon Press, Published in 1981, 1286 pages
141. Massive Stars and their Supernovae
     F. Thielemann, R. Hirschi, M. Liebendorfer, R. Diehl | arXiv, Published in 2010, 81 pages
142. Dwarf-Galaxy Cosmology
     Regina Schulte-Ladbeck, at al. | Hindawi Publishing, Published in 2010, 238 pages
143. Introduction to Dark Matter Experiments
     R. W. Schnee | arXiv.org, Published in 2011, 64 pages
144. Cosmology: The Study of the Universe
     | NASA, Published in 2009, 38 pages
145. A Simple Guide to Backyard Astronomy
     Carol Beigel | , Published in 2008, 61 pages
146. Cosmic Microwave Background Anisotropies up to Second Order
     Nicola Bartolo, Sabino Matarrese, Antonio Riotto | arXiv, Published in 2007, 53 pages
147. Gamma-Ray Bursts: Progress, Problems and Prospects
     Bing Zhang, Peter Meszaros | arXiv, Published in 2008, 87 pages
148. An Exposition on Inflationary Cosmology
     Scott Watson | arXiv, Published in 2000, 93 pages
149. Mechanism of the Heavens
     Mary Somerville | J. Murray, Published in 1831, 710 pages
150. The Complete Idiot's Guide to The Sun
     Jay M. Pasachoff | Alpha, Published in 2003, 350 pages
151. Voyager 1 and 2: Atlas of Six Saturnian Satellites
     Raymond M. Batson | NASA, Published in 1984, 175 pages
152. Introduction to the Theory of Black Holes
     Gerard 't Hooft | Utrecht University, Published in 2009, 49 pages
153. Lectures on Inflation and Cosmological Perturbations
     David Langlois | arXiv, Published in 2010, 56 pages
154. Spherical Astronomy
     F. Brünnow | Van Nostrand, Published in 1865, 559 pages
155. The Fundamentals of Stellar Astrophysics
     George W. Collins, II | W H Freeman & Co, Published in 2003, 494 pages
156. Space Nomads
     Leota Jean LaPaz, Lincoln LaPaz | Holiday House, Published in 1961, 199 pages
157. Curiosities of the Sky
     Garrett Putman Serviss | Harper & Brothers, Published in 1909, 300 pages
158. Telescopic Work for Starlight Evenings
     William F. Denning | Taylor and Francis, Published in 1891, 372 pages
159. Gamma-Ray Bursts
     | Wikipedia, Published in 2014
160. Resources of Near-Earth Space
     J. S. Lewis, M. S. Matthews | University of Arizona Press, Published in 1993, 977 pages
161. An Introduction to Celestial Mechanics
     Richard Fitzpatrick | The University of Texas at Austin, Published in 2011, 216 pages
162. Understanding Galaxy Formation and Evolution
     V. Avila-Reese | arXiv, Published in 2006, 50 pages
163. Traces of Catastrophe
     Bevan M French | Lunar and Planetary Institute, Published in 1998, 120 pages
164. The Search for Extraterrestrial Intelligence, SETI
     Philip Morrison, John Billingham, John Wolfe | NASA, Published in 1979, 293 pages
165. Inflation
     Marieke Postma | NIKHEF, Published in 2009, 53 pages
166. Elements of Astrophysics
     Nick Kaiser | University of Hawaii, Published in 2002, 435 pages
167. Particle Physics Aspects of Modern Cosmology
     Robert H. Brandenberger | arXiv, Published in 1997, 70 pages
168. Are We Alone?
     Gregg Easterbrook | The Atlantic Monthly, Published in 1988
169. Cosmic Structure, Averaging and Dark Energy
     David L. Wiltshire | arXiv, Published in 2013, 55 pages
170. A Photographic Atlas of Rock Breakdown Features in Geomorphic Environments
     Mary Bourke, Heather Viles | Planetary Science Institute, Published in 2007, 88 pages
171. Gravitational Wave Detection by Interferometry
     Matthew Pitkin, Stuart Reid, Sheila Rowan, Jim Hough | arXiv, Published in 2011, 80 pages
172. Plasma Physics of Extreme Astrophysical Environments
     Dmitri A. Uzdensky, Shane Rightley | arXiv, Published in 2014, 56 pages
173. An Introduction to Celestial Mechanics
     Forest Ray Moulton | The MacMillan Company, Published in 1914, 437 pages
174. Supernova Cosmology: Legacy and Future
     Ariel Goobar, Bruno Leibundgut | arXiv, Published in 2011, 62 pages
175. Atlas of Peculiar Galaxies
     Halton C. Arp | California Institute of Technology, Published in 1966, 190 pages
176. Introduction to relativistic astrophysics and cosmology through Maple
     V. L. Kalashnikov | arXiv, Published in 2001, 124 pages
177. Short History of Astronomy
     Arthur Berry | John Murray, Published in 1898, 439 pages
178. Planetary Science: A Lunar Perspective
     Stuart Ross Taylor | Lunar and Planetary Institute, Published in 1982
179. Black Holes
     P.K. Townsend | arXiv, Published in 1997, 145 pages
180. Celestial Mechanics: Notes and Work
     J.D. Mireles James | Rutgers University, Published in 2007, 128 pages
181. Advances in Global and Local Helioseismology: an Introductory Review
     Alexander G. Kosovichev | arXiv, Published in 2011, 86 pages
182. The world according to the Hubble Space Telescope
     Mario Livio | arXiv.org, Published in 2008, 112 pages
183. Special Functions: Fractional Calculus and the Pathway for Entropy
     Hans J. Haubold (ed.) | MDPI AG, Published in 2018, 306 pages
184. An Overview of the Solar System
     | Wikipedia, Published in 2013
185. From Chaos to Consciousness: A Brief History of the Universe
     Mike Corwin | Bookboon, Published in 2015, 166 pages
186. Mars Science Laboratory
     | Wikipedia, Published in 2014
187. History of Astronomy
     George Forbes | , Published in 1909
188. Observing the Sky from 30S
     Roberto Mura | Wikibooks, Published in 2010, 86 pages
189. Protostars and Planets
     | Rice University, Published in 2015, 422 pages
190. An Introduction to the Theory of Rotating Relativistic Stars
     Eric Gourgoulhon | arXiv, Published in 2010, 88 pages
191. Cosmology
     V. A. Rubakov | arXiv.org, Published in 2018, 56 pages
192. Planetary Photometry
     Max Fairbairn | , Published in 2005
193. The Beginning and the End: The Meaning of Life in a Cosmological Perspective
     Clement Vidal | arXiv, Published in 2013, 356 pages
194. Solar Neutrinos
     V. Antonelli, L. Miramonti, C. Pena-Garay, A. Serenelli | arXiv, Published in 2012, 51 pages
195. Introduction to Cosmology
     David H Lyth | arXiv, Published in 1993, 53 pages
196. Primordial Nucleosynthesis: from precision cosmology to fundamental physics
     F. Iocco, G. Mangano, G. Miele, O. Pisanti, P.D. Serpico | arXiv, Published in 2009, 148 pages
197. Voyager 1 Encounters Saturn
     | NASA, Published in 1980, 51 pages
198. Images of the Solar Upper Atmosphere From SUMER on SOHO
     Uri Feldman, at al. | ESA Publications Division, Published in 2003, 209 pages
199. The Astrobiology Primer: An Outline of General Knowledge
     Lucas J. Mix, at al. | arXiv, Published in 2006, 79 pages
200. Lopsided Spiral Galaxies
     Chanda J. Jog, Francoise Combes | arXiv, Published in 2008, 75 pages
201. Everything You Always Wanted To Know About The Cosmological Constant Problem
     Jerome Martin | arXiv, Published in 2012, 89 pages
202. Cosmic Rays in Galactic and Extragalactic Magnetic Fields
     F. Aharonian, A. Bykov, E. Parizot, V. Ptuskin, A. Watson | arXiv, Published in 2011, 43 pages
203. When Biospheres Collide: A History of NASA's Planetary Protection Programs
     Michael Meltzer | NASA, Published in 2011, 542 pages
204. Encyclopedia of Astrophysics
     Søren Bertil F. Dorch | Scholarpedia, Published in 2009
205. Dynamics of the Universe in Problems
     Yu. L. Bolotin, et al. | UniverseInProblems.com, Published in 2013, 113 pages
206. High Energy Astrophysics
     Jonathan Katz | The Benjamin/Cummings Publishing, Published in 1986, 338 pages
207. Cosmic Rays and the Search for a Lorentz Invariance Violation
     Wolfgang Bietenholz | arXiv, Published in 2008, 81 pages
208. Astronomy
     Andrew Fraknoi, David Morrison, Sidney C. Wolff | Unglue.it, Published in 2016, 1200 pages
209. Great Astronomers
     Robert S. Ball | Isbister, Published in 1895, 392 pages
210. A Text-book of Astronomy
     George C. Comstock | D. Appleton and company, Published in 1901, 391 pages
211. A Review of the Universe: Structures, Evolutions, Observations, and Theories
     | universe-review.ca, Published in 2009
212. Mercury
     F. Vilas, C. Chapman, M. Matthews | University of Arizona Press, Published in 1989, 794 pages
213. Astronomy for Amateurs
     Camille Flammarion | D. Appleton and Company, Published in 1910
214. Chemistry in Protoplanetary Disks
     Thomas Henning, Dmitry Semenov | arXiv, Published in 2013, 84 pages
215. An Introduction to Quantum Cosmology
     D.L. Wiltshire | arXiv, Published in 2003, 60 pages
216. Practical Astronomy
     P. S. Michie, F. S. Harlow | John Wiley & Sons, Published in 1893, 246 pages
217. The First Stars
     Simon C. O. Glover | arXiv, Published in 2012, 72 pages
218. Celestial Mechanics
     J. B. Tatum | , Published in 2008
219. Mag 7 Star Atlas Project
     Andrew L. Johnson | , Published in 2007, 21 pages
220. High Performance Computing and Numerical Modelling
     Volker Springel | arXiv, Published in 2014, 108 pages
221. Elementary Mathematical Astronomy
     C. Barlow, G. Bryan | University Correspondence College Press, Published in 1893, 442 pages
222. The Elements of Theoretical and Descriptive Astronomy
     Charles J. White | J. Wiley, Published in 1909, 322 pages
223. Astrodynamics: A Compendium of Orbitology
     | Wikipedia, Published in 2013, 334 pages
224. A Briefer History of Time: From the Big Bang to the Big Mac
     Eric Schulman | St. Martin's Press, Published in 2004, 207 pages
225. A Handbook of Descriptive and Practical Astronomy
     George F. Chambers | Oxford At The Clarendon Press, Published in 1889, 756 pages
226. On the Origin (and Evolution) of Baryonic Galaxy Halos
     Duncan A. Forbes, Ericson D. Lopez | MDPI AG, Published in 2018, 232 pages
227. Trans-Neptunian Objects: An Overview
     | Wikipedia, Published in 2014
228. Advances in Modern Cosmology
     Adnan Ghribi | InTech, Published in 2011, 198 pages
229. Introduction to Early Universe Cosmology
     Robert H. Brandenberger | arXiv, Published in 2011, 70 pages
230. Habitable Planets for Man
     Stephen H. Dole | RAND Corporation, Published in 1964, 176 pages
231. The Telescope
     Louis Bell | McGraw-Hill, Published in 1922, 294 pages
232. Introductory Lectures on Quantum Cosmology
     J. J. Halliwell | arXiv, Published in 1990, 107 pages
233. Notes on Stellar Astrophysics
     James N. Pierce | Minnesota State University, Published in 2013, 299 pages
234. The Formation and Evolution of the Solar System
     James Schombert | University of Oregon, Published in 2007
235. Introduction to Millimeter/Sub-Millimeter Astronomy
     T. L. Wilson | arXiv, Published in 2009, 106 pages
236. Exoplanet Observing for Amateurs
     Bruce L. Gary | Reductionist Publications, Published in 2007, 170 pages
237. Through the Telescope
     James Baikie | Adam and Charles Black, Published in 1906, 303 pages
238. Ekpyrotic and Cyclic Cosmology
     Jean-Luc Lehners | arXiv, Published in 2009, 79 pages
239. Black-Hole Phenomenology
     Neven Bilic | arXiv, Published in 2006, 58 pages