QUESTION: For a school project we are planing a bioshere to put on Mars. What meetings have been held on this topic? I would also like as much reading information as you can give. ANSWER from Chris McKay on November 25, 1997: Here is a bit more than asked for but certainly a good place to look. I have attached to the bottom a copy of a paper I wrote on terraforming. Chris McKay NASA Ames Planetary Engineering Bibliography (Revised November 1995) Martyn J. Fogg (Probability Research Group, UK). Tom Meyer (University of Colorado), Stephen Gillett (MacKay School of Mines, Nevada), Robert Haynes (York University, Ontario). Contents 1. Non-Fiction Books 2. Recommended Fiction 3. Academic Papers 3.1 Geoengineering 3.2 Terraforming 3.3 Astrophysical Engineering / Other 4. Popular Articles 5. Unpublished Manuscripts and Conference Proceedings _________________________________________________________________ 1. Non-Fiction Books 1. Averner, M.M., and MacElroy. R.D., On the Habitability of Mars: An Approach to Planetary Ecosynthesis, NASA SP-414, 1976. 2. Clarke, Arthur C., The Snows of Olympus, Victor Gollancz Ltd, London, 1995. 3. Committee on Science, Engineering and Public Policy, Policy Implications of Greenhouse Warming, National Academy Press, 1991. 4. Fogg, Martyn J., Terraforming: Engineering Planetary Environments, SAE International, Warrendale, PA 1995. 5. Hargrove, Eugene C., ed., Beyond Spaceship Earth: Environmental Ethics and the Solar System, Sierra Club Books, San Francisco, 1986. 6. Oberg, James E., New Earths, Stackpole, 1981, New American Library 1983. 7. The Terraforming of Planets, Man-made Biospheres and The Future Civilization, Yazawa Science Office, Tokyo, 1992. (In Japanese with sections by Fogg, McKay and Smith). 2. Recommended Fiction 1. Benford, Gregory, The Jupiter Project, TOR Books, New York, 1975. 2. Clarke, Arthur, C., The Sands of Mars, Sidgewick and Jackson Ltd., 1951. 3. Heinlein, Robert, Farmer in the Sky, First published 1950, Modern Edition, Victor Gollancz Ltd, 1990. 4. Lovelock, James, and Michael Allaby, The Greening of Mars, St. Martin's Press, 1984 and Warner Books, New York, 1984. 5. Robinson, Kim Stanley, Red Mars, Bantam Spectra Books, New York, 1993. 6. Robinson, Kim Stanley, Green Mars, Harper Collins Publishers, London, 1993. 7. Sargent, Pamela, Venus of Dreams, Bantam Spectra Books, New York, 1986. 8. Sargent, Pamela, Venus of Shadows, Bantam Spectra Books, New York, 1990. 9. Stapledon, Olaf, Last and First Men, First Published 1930, Modern Edition, Pelican Books, 1987. 10. Turner, Frederick, Genesis, Saybrook Publishing Company, Dallas 1988. 3. Academic Papers 3.1 Geoengineering 1. Cathcart, Richard B., "Macroengineering and Terraforming: Building Modernised and Additional Functional Regions", Speculations in Science and Technology, 14, 34-40, 1991. 2. Charlson, R.J., Schwartz, S.E., Hales, J.M., Cess, R.D., Coakley, J.A., Hansen, J.E. and Hofmann, D.J., "Climate Forcing by Anthropogenic Aerosols," Science, 255, 423-430, 1992. 3. Cicerone, Ralph J., Elliott, Scott and Turco, Richard P., "Reduced Antarctic Ozone Depletions in a Model with Hydrocarbon Injections", Science, 254, 1191-1194, 1991. 4. Cicerone, Ralph J., Elliott, Scott and Turco, Richard P., "Global Environmental Engineering", Nature, 356, 9, 1992. 5. Dyson, Freeman, "Can We Control the Carbon Dioxide in the Atmosphere?" Energy, 2, 287-291, 1977. 6. Early, James T., "Space-based Solar Shield to Offset Greenhouse Effect", Journal of the British Interplanetary Society, 42, 567-569, 1989. 7. Ehricke, Krafft A., "Space Light: Space Industrial Enhancement of the Solar Option," Acta Astronautica, 6, 1515-1633 (1979). 8. Ehricke, Krafft A., "Contributions of Space Reflector Technology to Food Production, Local Weather Manipulation and Energy Supply, 1985-2020", Journal of the British Interplanetary Society, 34, 511-518, 1981. 9. Huagan, Peter M. and Drange, Helge, "Sequestration of CO2 in the deep Ocean by Shallow Injection", Nature, 357, 318-320, 1992. 10. Hudson, H.S., "A Space Parasol as a Countermeasure Against the Greenhouse Effect", Journal of the British Interplanetary Society, 44, 139-141, 1991. 11. Jarvis, P.G., "Atmospheric Carbon Dioxide and Forests," Phil. Trans. R. Soc. Lond. B., 324, 369-392, 1989. 12. Joos, F., Sarmiento, J.L. and Siegenthaler, U., "Estimates of the Effect of Southern Ocean Iron Fertilization on Atmospheric CO2 Concentrations," Nature, 349, 772-775, 1991. 13. Kolber, Zbigniew S., et al., "Iron Limitation of Phytoplankton Photosynthesis in the Equatorial Pacific Ocean," Nature, 371, 145-149, 1994. 14. Marchetti, Cesare, "On Geoengineering and the CO2 Problem," Climatic Change, 1, 59-68, 1977. 15. Martin, John H., Fitzwater, Steve E. and Gordon, R., Michael, "Iron Deficiency Limits Phytoplankton Growth in Antarctic Waters," Global Biogeochemical Cycles, 4, 5-12, 1990. 16. Martin, John H., Gordon, R. Michael and Fitzwater, Steve E., "Iron in Antartic Waters," Nature, 345, 156-158, 1990. 17. Martin, John H., et al., "Testing the Iron Hypothesis in Ecosystems of the Equatorial Pacific Ocean," Nature, 371, 123-129, 1994. 18. Mautner, Michael and Parks, Kelly, "Space-based Control of the Climate", in Engineering, Construction and Operations in Space II: Volume 2, Proceedings of Space '90, American Society of Civil Engineers, 1990. 19. Mautner, Michael, "A Space-based Solar Screen Against Climatic Warming", Journal of the British Interplanetary Society, 44, 135-138, 1991. 20. Morel, F.M.M., Reinfelder, J.R., Roberts, S.B., Chamberlain, C.B., Lee, J.G. and Yee, D., "Zinc and Carbon Co-limitation of Marine Phytoplankton," Nature, 369, 740-742, 1994. 21. Peng, T-H. and Broecker, W.S., "Dynamical Limitations on the Antarctic Iron Fertilization Strategy," Nature, 349, 227-229 (1991). 22. Penner, S.S., Schneider, A.M. and Kennedy E.M., "Active Measures for Reducing the Global Climatic Impacts of Escalating CO2 Concentrations," Acta Astronautica, 11, 345-348, 1984. 23. Sarmiento, J.L., "Slowing the Buildup of CO2 in the Atmosphere by Iron Fertilization: A Comment," Global Biogeochemical Cycles, 5, 1-2, 1991. 24. Seifritz, Walter, "Mirrors to Halt Global Warming?" Nature, 340, 603, 1989. 25. Stix, Thomas H., "Removal of Chlorofluorocarbons from the Earth's Atmosphere,"J. Appl. Phys., 66, 5622-5626, 1989. 26. Watson, Andrew. J., et al., "Minimal Effect of Iron Fertilization on Sea-Surface Carbon Dioxide Concentations," Nature, 371, 143-145, 1994. 27. Wong, A.Y., Sensharma, D.K., Tang, A.W., Suchannek, R.G. and Ho, D., "Observation of Charge-Induced Recovery of Ozone ConcentrationAfter Catalytic Destruction by Chlorofluorocarbons," Physical Review Letters, 72, 3124-3127, 1994. 3.2 Terraforming 1. Adelman, Saul, "Can Venus Be Transformed into an Earth-Like Planet?", Journal of the British Interplanetary Society, 35, 3-8, 1982. 2. Adelman, Benjamin and Adelman, Saul J., "Some Research Requirments of Planetary Engineering", Journal of the British Interplanetary Society, 42, 555-557, 1989. 3. Balasubramanian, D., "Should Mars be Made Habitable?" Current Science, 61(11), 712-714 (1991). 4. Birch, Paul, "Terraforming Venus Quickly", Journal of the British Interplanetary Society, 44, 157-167, 1991. 5. Birch Paul, "Terraforming Mars Quickly", Journal of the British Interplanetary Society, 45, 331-340, 1992. 6. Birch, Paul, "How to Spin a Planet", Journal of the British Interplanetary Society, 46, 311-313, 1993. 7. Birch, Paul, "How to Move a Planet", Journal of the British Interplanetary Society, 46, 314-316, 1993. 8. "Bringing Worlds to Life: Terraforming, the New Science of Planetary Environmental Engineering", Abstracts of London University Conference, Journal of the British Interplanetary Society, 46, 327-328, 1993. 9. Burns, Joseph and Harwit, Martin, "Towards a More Habitable Mars -or- the Coming Martian Spring", Icarus, 19, 126-130, 1973. 10. Fogg, M. J., "Terraforming Mars: Conceptual Solutions to the Problem of Plant Growth in Low Concentrations of Oxygen,"Journal of the British Interplanetary Society, 48(10), 427-434, 1995. 11. Dyson, Freeman, "Terraforming Venus", Correspondence in Journal of the British Interplanetary Society, 42, 593, 1989. 12. Fogg, Martyn J., "The Terraforming of Venus", Journal of the British Interplanetary Society, 40, 551-564, 1987. 13. Fogg, Martyn J., "The Creation of an Artificial, Dense Martian Atmosphere: A Major Obstacle to the Terraforming of Mars", Journal of the British Interplanetary Society, 42, 577-582, 1989. 14. Fogg, Martyn J., "Terraforming, as Part of a Strategy for Interstellar Colonisation", Journal of the British Interplanetary Society, 44, 183-192, 1991. 15. Fogg, Martyn J., "Terraforming and the Future Offspring of Gaia", Gaian Science, 2(3), 8-9, 1991. 16. Fogg, Martyn J., "A Synergic Approach to Terraforming Mars", Journal of the British Interplanetary Society, 45, 315-329, 1992. 17. Fogg, Martyn J., "Terraforming: A Review for Environmentalists", The Environmentalist 13, 7-17, 1993. 18. Fogg, Martyn J., "Dynamics of a Terraformed Martian Biosphere", Journal of the British Interplanetary Society, 46, 293-304, 1993. 19. Freitas, Robert A., Jr., "Terraforming Mars and Venus Using Machine Self-Replicating Systems", Journal of the British Interplanetary Society, 36, 139-142, March 1983. 20. Friedmann, E. Imre, Hua, M. and Ocampo-Friedmann, R., "Terraforming Mars: Dissolution of Carbonate Rocks by Cyanobacteria", Journal of the British Interplanetary Society, 46, 291-292, 1993. 21. Friedmann, E. Imre and Ocampo-Friedmann, R., "A Primitive Cyanobacterium as Pioneer Microorganism for Terraforming Mars", Adv. Space Res, in press, 1993. 22. Gillett, Stephen L., "Establishment and Stabilization of Earthlike Conditions on Venus", Journal of the British Interplanetary Society, 44, 151-156, 1991. 23. Hansson, Anders, "A Fresh Start on Mars," Chapter 10 in Mars and the Development of Life, Ellis Horwood, Chichester, 1991. 24. Haynes, Robert H., "Prospects for Establishing a Microbial Ecosystem on Mars," in Biotechnology on the Threshold of the XXI Century, Conference Proceedings, pp. 85-88, Moscow, 1989. 25. Haynes, Robert H., "Ecce Ecopoiesis: Playing God on Mars", in MacNiven, D., (ed), Moral Expertise, pp. 161-183, Routledge, New York, 1990. 26. Haynes, Robert H., "Etablierung von Lieben auf dem Mars durch gerichtete Panspermie: Technische und ethische Probleme der Okopoese," Biol. Zent. bl, 109, 193-205, 1990. (In German.) 27. Haynes, Robert H., "Una Nova Ecopoesi: Possibilitats de Transmetre Vida a Mart," Treballs de la SCB., 43, 11-23 (1992). (In Catalan.) 28. Haynes, Robert H. and McKay, Christopher, P., "The Implantation of Life on Mars: Feasibility and Motivation", Adv. Space Res., 12, (4)133-(4)140, 1992. 29. Heath, Martin, "Terraforming: Plate Tectonics and Long-Term Habitability," Journal of the British Interplanetary Society, 44, 147-150, 1991. 30. Hope-Jones, E.F., "Planetary Engineering," Journal of the British Interplanetary Society, 12, 155-159, 1953. 31. Jukes, Thomas, H., "Mars as a New Abode for Microbial Life," J. Molec. Evol., 32, 355-357, 1991. 32. Kuhn, W.R., Rogers, S.R., MacElroy, R.D., "The Response of Selected Terrestrial Organisms to the Martian Environment: A Modeling Study," Icarus, 37, 336-346, 1979. 33. Levine, Joel S., "The Making of the Atmosphere", in Advances in Engineering Science, Vol 3, NASA CP-2001, 1191-1202 (1976). 34. Levine, Joel S., "Mars: Past, Present and Future", in E.B. Pritchard (Ed), Progress in Astronautics and Aeronautics, 145, 17-26, (1993). 35. Lovelock, James E., "Geophysiology: A New Look at Earth Science", Bulletin of the American Meteorological Society, 67(4), 392-397, 1986. 36. Lovelock, James E., "The Ecopoiesis of Daisy World", Journal of the British Interplanetary Society, 42, 583-586, 1989. 37. MacElroy, R.D and Averner, M.M, "Atmospheric Engineering of Mars", in Advances in Engineering Science, Vol 3, NASA CP-2001, 1203-1214, 1976. 38. Marchal, C., "The Venus-New-World Project", Acta Astronautica, 10(5-6), 269-275, 1983. 39. Margulis, Lynn and West, Oona, "Gaia and the Colonization of Mars", GSA Today, 3,(11), 277-291, 1993. 40. McKay, Christopher P., "On Terraforming Mars", Extrapolation, 23(4), Kent State University Press, 1982. 41. McKay, Christopher P., "Terraforming Mars", Journal of the British Interplanetary Society, vol. 35, pp. 427-433, 1982. 42. McKay, Christopher P., "Using Microorganisms to Make an Earth of Mars," in Biotechnology on the Threshold of the XXI Century, Conference Proceedings, pp. 89-91, Moscow, 1989. 43. McKay, Christopher P., "Does Mars Have Rights? An Approach to the Environmental Ethics of Planetary Engineering", in MacNiven, D., (ed), Moral Expertise, pp. 184-197, Routledge, New York, 1990. 44. McKay, Christopher P. and Haynes, Robert, H., "Should we Implant Life on Mars?" Scientific American, 263(6), 144, 1990. 45. McKay, Christopher P., Toon, Owen.B. and Kasting, James, F., "Making Mars Habitable", Nature, 352, 489-496, 1991. 46. McKay, Christopher P., and Stoker, Carol R., "Gaia and Life on Mars," in Schneider, S.H. and Boston, P.J. (eds), Scientists on Gaia, pp. 375-381, M.I.T. Press, 1991. 47. McKay, Christopher P., "Restoring Mars to Habitable Conditions: Can we? Should we? Will we?" Journal of the Irish Colleges of Physicians and Surgeons, 22(1), 17-19, 1993. 48. Mole, R. A., "Terraforming Mars with Four War Surplus Bombs," Journal of the British Interplanetary Society, 48(7), 321-324, 1995. 49. Morgan, Charles R., "Terraforming with Nanotechnology," Journal of the British Interplanetary Society, 47, 311-318, 1994. 50. Nussinov, M.D., Zemlya i Vselennaya, 6, 57-61, 1981. (In Russian.) 51. Nussinov, M.D., Lysenko, S.V. and Patrikeev, V.V., "Terraforming of Mars Through Terrestrial Microorganisms and Nanotechnological Devices," Journal of the British Interplanetary Society, 47, 319-320, 1994. 52. Oberg, James E., "Terraforming", in Hart, M.H. and Zuckerman, B., Extraterrestrials: Where Are They?, pp. 62-65, Pergamon Press, New York, 1982. 53. Pollack, James B. and Sagan, Carl, "Planetary Engineering", in Lewis, J. and Matthews, M. (eds), Resources of Near-Earth Space, University of Arizona Press, in press. 54. Sagan, Carl, "The Planet Venus", Science, 133, 849-858, 1961. 55. Sagan, Carl, "Planetary Engineering on Mars", Icarus, 20, 513, 514 1973. 56. Semenov, N.N., Changes in the Martian atmosphere, in B.P. Konstantinov, V.D. Pekelis, eds., Inhabited Space, Part I, p. 192, NASA TT-F-819, Feb. 1975. 57. Smith, Alexander G, "Transforming Venus by Induced Overturn", Journal of the British Interplanetary Society, 42, 571-576, 1989. 58. Smith, Alexander G, "Time, Ice and Terraforming", Journal of the British Interplanetary Society, 46, 305-310, 1993. 59. Taylor, Richard L.S., "Paraterraforming: The Worldhouse Concept," Journal of the British Interplanetary Society, 45, 341-352, 1992. 60. Thomas, D. J., "Biological Aspects of the Ecopoeisis and Terraformation of Mars: Current Perspectives and Research,"Journal of the British Interplanetary Society, 48(10), 427-434, 1995. 61. Vondrak, Richard, "Creation of an Artificial Lunar Atmosphere", Nature, 248, 657-659, 1974. 62. R.R. Vondrak, "Creation of an Artificial Atmosphere on the Moon", in Advances in Engineering Science, Vol 3, NASA CP-2001, 1215-1224 (1976). 63. Zubrin, R., "The Economic Viability of Mars Colonization,"Journal of the British Interplanetary Society, 48(10), 407-414, 1995. 64. Zubrin, Robert and McKay, Christopher P., "Technological Requirements for Terraforming Mars", Journal of the British Interplanetary Society, in press. 3.3 Astrophysical Engineering / Other 1. Ahrens, Thomas J. and Harris, Alan W., "Deflection and Fragmentation of Near-Earth Asteroids", Nature, 360, 429-433, 1992. 2. Beech, Martin, "Blue Stragglers as Indicators of Extraterrestrial Civilizations," Earth, Moon and Planets, 49, 177-186, 1990. 3. Beech, Martin, "Aspects of an Asteroengineering Option", Journal of the British Interplanetary Society, 46, 317-322, 1993. 4. Birch, Paul, "Supramundane Planets", Journal of the British Interplanetary Society, 44, 169-182, 1991. 5. Cathcart, Richard B., "A Megastructural End to Geological Time", Journal of the British Interplanetary Society, 36, 291-297, 1983. 6. Criswell, D.R., "Solar System Industrialization: Implications for Interstellar Migrations," in Finney, R and Jones, E.M. (eds), Interstellar Migration and the Human Experience, pp. 50-87, University of California Press, Berkeley, 1985. 7. Dyson, Freeman J., "Gravitational Machines," in Cameron, A.G.W. (ed), Interstellar Communication, pp. 115-120, W.A. Benjamin Inc., New York, 1963. 8. Dyson, Freeman J., "The Search for Extraterrestrial Technology," in Marshak, R.E. (ed), Perspectives in Modern Physics, pp. 641-655, Interscience Publishers, New York, 1966. 9. Dyson, Freeman J., "The World the Flesh and the Devil", Section IV, "Big Trees", in Sagan, C., (ed), Communication With Extraterrestrial Intelligence - CETI, pp. 380-383, M.I.T. Press, 1973. 10. Ehricke, K.A., A Long-Range Perspective on Some Fundamental Aspects of Interstellar Evolution, Journal of the British Interplanetary Society, 28, 722, 1975. 11. Fogg, Martyn J., "Stellifying Jupiter: A First Step to Terraforming the Galilean Satellites", Journal of the British Interplanetary Society, 42, 587-592, 1989. 12. Fogg, Martyn J., "Solar Exchange as a Means of Ensuring the Long Term Habitability of the Earth", Speculations in Science and Technology 12, 153-157, 1989. 13. Froman, D., "The Earth as a Man-Controlled Space Ship," Physics Today, 15, 19-22, 1962. 14. Mautner, Michael, "Directed Panspermia: A Technical Evaluation of Seeding Nearby Solar Systems," Journal of the British Interplanetary Society, 32, 419-422, 1979. 15. Mautner, M. N., "Directed Panspermia.2. Technological Advances Toward Seeding Other Solar Systems and the Foundation of Panbiotic Ethics,"Journal of the British Interplanetary Society, 48(10), 1995. 16. Melosh, H.J. and Nemchinov, I.V., "Solar Asteroid Diversion," Nature, 366, 21-22, 1993. 17. Sagan, C. and Ostro, S.J., "Dangers of Asteroid Deflection," Nature, 368, 501, 1994. 18. Shkadov, L.M., "Possibility of Controlling Solar System Motion in the Galaxy", IAA-87-613, 1987. 19. Solem, Johndale C., "Interception of Comets and Asteroids on Collision Course with Earth", J. Spacecraft and Rockets, 30, 222-229, 1993. 4. Popular Articles 1. Adelman, Benjamin, and Saul J. Adelman, "'The Case for Planetary Engineering", Space World, pp. 20 ff., Vol. S-6-222, June/July 1982. 2. Adelman, Saul, "Terraforming Venus," Spaceflight, 24, 50-53, 1982. 3. Benford, Gregory, "The Future of the Jovian System", Issac Asimov's Science Fiction Magazine, 11(8), 62-81, 1987. 4. Berry, Adrian, "Venus, The Hell-World," and "Making it Rain in Hell," Chapters 6 & 7 in The Next Ten Thousand Years, New American Library, 1984. 5. Darrach, B., Petranek, S. and Hollister, A., "Mars: Bringing a Dead World to Life,"LIFE, 14(5), 24-38, 1991. 6. Dyson, Freeman, Disturbing the Universe, Chapter 18, Harper and Row Ltd, 1979. 7. Fogg, Martyn J., "Stellifying Jupiter", Analog, CIX(10), 73-83, 1989. 8. Fogg, Martyn J., "Astrophysical Engineering and the Fate of the Earth", Analog, CX(6), 53-63, 1990. 9. Fogg, Martyn J., "The Problem of Terraforming", Spaceflight, 33(7), 244-247, 1991. 10. Fogg, Martyn J., "Once and Future Mars", Analog, CXI(1&2), 109-122, 1991. 11. Gillett, Stephen L., "Second Planet, Second Earth", Analog, CIV(12), 64-78, 1984. 12. Gillett, Stephen L., "The Postdiluvian World", Analog, CV(11), 40-58, 1985. 13. Gillett, Stephen L., "Inward Ho!", Analog, CIX(13), 62-72, 1989. 14. Gillett, Stephen L., "Refuelling a Rundown Planet", Analog, CXI(10), 81-77, 1991. 15. Gillett, Stephen L., "Titan as the Abode of Life", Analog, CXII(13), 40-55, 1992. 16. Gillett, Stephen L., "Red Planet, Green Planet", Amazing, pp. 66-68, Jun 1992. 17. Gillett, Stephen L., "The (Re)Wetting of Venus", Amazing, pp. 64-67, Jul 1992. 18. Gillett, Stephen L., "The Ethics of Terraforming", Amazing, 72-74, Aug 1992. 19. Hamil, Ralph, "Terraforming the Earth", Analog, July 1978, pp. 47-65. 20. Haynes, Robert, "How Mars Might Become a Home for Humans," in The Illustrated Encyclopedia of Mankind, in press, 1993. 21. Kross, John F., "Heaven from Hell", Ad Astra, 4(3), 22-24, 1992. 22. Lovelock, James E., "The Second Home", Chapter 8 in The Ages of Gaia, Oxford University Press, 1988. 23. McKay, Christopher P., "Terraforming: Making an Earth of Mars", The Planetary Report, VII(6), 26-27, 1987. 24. Oberg, James E., "Colony on the Planet Epaphos", Star and Sky, March 1980, page 16. 25. Oberg, James E., "The Concept of Terraforming",Aviation/Space, 1981. 26. "Pioneers and Settlers," Chapter 2 in Starbound, Voyage Through the Universe Series, Time-Life Books, Alexandria, Virginia, 1992. 27. Savage, Marshall, "Elysium," Chapter 5 in The Millenial Project, Empyrean Publishing, Denver, 1993. 28. Terra, Richard P, "Islands in the Sky: Human Exploration and Settlement of the Oort Cloud", Analog, CXI, 69-85, 1991. 29. Turner, Frederick, "Life on Mars. Cultivating a Planet - and Ourselves", Harper's Magazine, 279(1671), 33-40, 1990; also in Tempest, Flute and Oz: Essays on the Future, Persea Books, New York, 1991. 30. Zubrin, Robert M., "The Outer Solar System and the Human Future", Ad Astra, 5(2), 18-23, 1993. 31. Zubrin, Robert M. and McKay, Christopher P., "A World for the Winning: The Exploration and Terraforming of Mars", The Planetary Report XII(5), 16-19, 1992. 32. Zubrin, Robert M. and McKay, Christopher P., "Pioneering Mars", Ad Astra, 4(6), 34-41, 1992. 33. Zubrin, Robert M. and McKay, Christopher P., "Terraforming Mars," Analog, CXIV(5), 70-87, 1994. 5. Unpublished Manuscripts and Conference Proceedings (T-I = First Terraforming Colloquium, Houston, 1979.) (T-II = Second Terraforming Colloquium, Houston, 1987.) 1. Adelman, Saul, "Can Venus Be Transformed into an Earth-Like Planet?", Updated comments, T-II, 1987. 2. Averner, M.M., and MacElroy, R.D., On the Habitability of Mars: A Post-Viking Reassessment, manuscript, 1980, update T-II, 1987. 3. Cathcart, Richard B., "The Most Familiar Planet", T-II, 1987. 4. Cobleigh, T. & Warner, J., "Ethical Aspects of Terraforming", T-I, 1979. 5. Fogg, Martyn J., "Terraforming Mars - Problems With Paradigms", MS written for presentation at NASA Workshop on Terraforming Mars, Ames Research Center, June 1991. 6. Fogg, Martyn J., "The Long-Term Habitation of Mars", MS written for presentation at Case for Mars V, 1993. 7. Gillett, Stephen L., "Terraforming Venus", T-II, 1987. 8. Hamil, Ralph, "Terraforming the Earth", update for T-II, 1987. 9. Hansen, James, "Can the Climate be Engineered?" Invited talk at American Geophysical Union, Dec 9, 1991. 10. Hiscox, Julian, "Genetic Engineering Requirements for Minimum' Ecopoiesis on Mars," preliminary report, 1993. 11. Hiscox, J. A. and Thomas, D. J., "Genetic Modification and Selection of Microorganisms for Growth on Mars,"Journal of the British Interplanetary Society, 48(10), 419-426, 1995. 12. Krasnoshtein, Flora, "Making the Red Planet Green," York University, Ontario, 1991. 13. MacNiven, Don, "Environmental Ethics and Ecopoiesis", York University, Ontario, 1987. 14. MacNiven, D., "Environmental Ethics and Planetary Engineering,"Journal of the British Interplanetary Society, 48(10), 441-443, 1995. 15. McKay, Christopher P., "Can Trace Gases Be used to Warm Mars?", privately circulated, 1985. 16. Oberg, James E., "Planetary Engineering in Pre-SF Literature", 1980. 17. Oberg, James, and Gillett, Steve, "Better Homes and Planets: 1001 Questions About Terraforming You Were Afraid to Ask," MS, 1987. 18. Strickland, John K., Jr., "Terraforming: Some Organizing Concepts and Speculations", T-II, 1987. 19. Thomas, D.J., "The Ecopoiesis and Terraformation of Mars: Current Perspectives and Research", NASA Planetary Biology Internship Program MS, 1993. _________________________________________________________________ McKay, C.P., Restoring Mars to habitable conditions: Can we? Should we? Will we? J. Irish Colleges of Physicians and Surgeons, 22, 17-19, 1993. Correspondence to: Christopher P. McKay Mail Stop 245-3 NASA Ames Research Center Moffett Field CA 94035 USA Exploration of the Solar System by spacecraft (now complete except for Pluto) indicates that Earth is the only planet with life. However, there is one intriguing aspect to this otherwise lifeless story: Mars appears to have been habitable early in its history. Photographs of the Martian surface from orbit show ancient river features, now dry and covered with craters, that are testimony of this early clement environment. The fact that liquid water existed on the surface of Mars at about the same period of time that life appeared on Earth (over 3.5 thousand million years ago) is arguably the most interesting biological fact we know about the other planets. So the search for fossils on Mars has begun and aspires to be the main motivation --- or scientific rationalization --- for human exploration of Mars. The observation that Mars was once a habitable world leads us to ponder how Mars became the cold harsh desert it is today and to speculate under what conditions, natural or artificial, it could be restored to a habitable state. Humanity has now demonstrated that it is capable of inadvertent modification of environments on planetary scales. Furthermore, there are now suggestions that we undertake purposeful global engineering efforts to redress, or at least mitigate, the untoward effects of our past actions, in particular with respect to the planetary greenhouse and the ozone layer (1,2). Couple this development with the recent call for human exploration of Mars --- and the suggestion of a past habitable state on that planet --- and the question of `terraforming' Mars is not so out of place. In a recent paper my colleagues and I attempted to address terraforming Mars in a rigorous scientific manner, limiting our discussion to current technologies (3). Under this restriction it is not possible to alter the basic physical parameters of a planet; its mass, distance from the sun, rotation rate, etc.. It is equally impossible to import materials from which to build a planetary atmosphere or hydrosphere. For example, the transport to Mars of an atmosphere with a surface pressure equal to sea level on Earth would require 10^15 tons. Compare this to the lifting capability to low Earth orbit of about 100 tons for the biggest rocket currently available, the Soviet Energiya. The only thing way to engender a habitable state on Mars is to affect the distribution of elements and compounds already present and thereby alter the climate and chemical state of the planet --- which is what we are doing on Earth. As we considered the question of terraforming Mars, it became clear that there are two potentially habitable states for that planet. One, suitable for plants and microorganisms, would have a thick atmosphere composed primarily of carbon dioxide with small amounts of nitrogen and oxygen as needed for fixation and plant respiration, respectively. Such an atmosphere would be similar to what we believe existed on Mars during its early history and would also be similar to the conditions thought to prevail on the early Earth until the rise of oxygen sometime near the end of the Precambrian, about a thousand million years ago. Such an atmosphere would be warm and would provide enough pressure that humans would not need a space suit, but it would not be breathable. The other possible habitable state would be one with an Earth-like mixture of gases in the atmosphere with carbon dioxide set to the upper limit of long term human tolerance, about 1% (3,4). Without the thick carbon dioxide greenhouse this atmosphere cools to --55 degc, much too cold to support life. Warming the planet would require augmentation of the carbon dioxide greenhouse effect. A practical way to do this was proposed in 1984 by James Lovelock (5), famous for his Gaia hypothesis of life on Earth, in a science fiction novel in which Earth exported its chlorofluorocarbons compounds to Mars on ballistic missiles rendered obsolete by the end of the Cold War. While Lovelock was prescient in anticipating that these missiles would soon be `available,' his scheme for transporting materials from Earth to Mars fails from the sheer mass of matter that must be carried. If the needed CFCs could be manufactured on Mars, then the scheme could work. Our calculations (3) indicate that a suite of four existing CFCs could warm Mars significantly, but to warm it to habitable levels a mixture of specially developed compounds would be needed. Obviously, on Earth, CFCs have not been designed to optimize their greenhouse effects and if some effort were directed this way it could be that a suitable combination of gases would be found. Solar ultraviolet light would destroy these molecules and they would need to be reformed continuously (3). Thus, an oxygen-rich atmosphere aided by the artificial greenhouse gases could provide an atmosphere on Mars that is thick and warm and breathable by humans and other animals. Are there enough of the needed elements on Mars --- carbon dioxide, water, and nitrogen --- to provide the raw materials for the construction of either of these hypothetical habitable states? The published range of estimates as to the amount of these compounds varies considerably (3,6). Review of these estimates suggest that there probably is ample carbon dioxide and water on Mars to produce a habitable state (3). The question of nitrogen is more difficult to assess, but the upper range of estimates allows for enough of this gas to construct an Earth-like atmosphere. The question of nitrogen abundance on Mars is the key issue that must be resolved on future missions as part of any further assessment of Mars' terraforming potential. If habitable states exist and there are sufficient supplies of the needed resources, how could the present Mars be transformed? We envision two phases to this process. The first phase would be the warming of the planet and the release of any carbon dioxide held in the polar caps and the soil. The second phase would be the conversion of this carbon dioxide into oxygen and the buildup of nitrogen in the atmosphere. The warming of Mars might be accomplished by producing the CFCs discussed above in the context of warming an oxygen-rich atmosphere. We have calculated that it would be possible to warm the present Mars sufficiently with these gases so that any carbon dioxide resident in the permanent polar caps or in the soil would enter the atmosphere. This carbon dioxide would enhance the greenhouse effect, further warming the planet. If there was enough carbon dioxide available to provide for a surface pressure on Mars of about twice Earth sea level, then the temperature of the planet would reach habitable limits. The production of CFCs could stop and Mars would maintain this habitable state --- the planet would be resuscitated. If it was decided that restoring the thick primordial carbon dioxide atmosphere on Mars was only the penultimate goal then transforming the carbon dioxide into oxygen using plants would begin. There are difficulties with this proposition. First, in order for there to be a net production of oxygen, there must be a concomitant sequestering of reduced carbon or the reaction will merely reverse itself and consume the oxygen produced. It is not clear how this could be done on Mars without deep ocean basins and efficient burial processes, which on Earth are associated with plate tectonics, absent on Mars. Futher, if a suitable sink for the reduced carbon produced by photosynthesis on Mars was found, it would take a long time for the buildup of oxygen to reach significant levels. A simple estimate of the time required is obtained from the average efficiency with which ecosystems on Earth convert solar energy into fixed carbon, 0.01% (7). At this efficiency it would take about 100,000 years of Martian sunlight to produce an oxygen-rich atmosphere on Mars (3). The warming of Mars is a more achievable task because the greenhouse effects involved in warming Mars are fairly efficient at trapping solar energy and because there is a positive feedback between warming the planet and releasing carbon dioxide from the polar caps and the soil. Warming Mars to habitable temperatures may only require a few centuries (3). It is important to appreciate that solar energy is the only plausible power source for terraforming Mars. The 10^16 Watts of solar power on Mars is over 10 thousand times the world electrical power and exceeds the energy in the combined nuclear weapons of the world in about 30 mins. If Mars was made habitable it is likely that the processes that resulted in the deterioration of its initial habitable state would again act to destroy the newly salubrious environments. We estimate that this would take about 100 million years (3,6). Recidivisism on this timescale may be acceptable. The main conclusion from our work (3) briefly summarized above is that our current knowledge of Mars suggests that it is possible to transform that planet into one of at least two habitable states using technologies that we are already demonstrating, probably to our detriment, on the Earth. Should we do so? I have found it interesting to pursue this question within the scope of environmental ethics (8,9,10). We must consider that Mars has no life today (more on this later) and we are proposing to introduce life there. This is a situation novel in environmental ethics, which has heretofore only considered human interactions with systems that were biologically complete prior to human activity. On Earth the status quo ante and a living world are the same. Environmental principles that place value on life do not conflict with environmental principles that attempt to restrain human activity. For terraforming Mars the situation is the obverse: there the status quo, nature as humans first found it, is lifeless and we have the possibility of introducing (or re-introducing) life there. Faced with this critical difference between Earth-bound environmental ethics and the problem of Mars it is not possible to utilize the great body of literature in environmental ethics directly. One must instead distill this to a set of basic axioms from which one can then generalize as to the appropriateness of terraforming Mars. From my own reading of the ethics literature I have suggested (8) that principles of environmental ethics are based on some combination of three fundamental axioms: 1) Anti-humanism, the notion that human action is inevitably harmful; 2) Stewardship, a requirement that humans must use nature wisely for their own benefit; and 3) Intrinsic worth, the supposition that some class of objects have intrinsic worth regardless of their utility to humans. The translation of the first two axioms to the question of terraforming Mars is straightforward but becomes more difficult for the third. Invoking intrinsic worth as a basis for environmental thought is a fairly recent development (11) and has heretofore focused on living things and their assemblages as the class of objects with intrinsic value. In this case, a living Mars is of more intrinsic worth than a lifeless Mars and restoring life to that planet is ethically motivated. However, one could conceive of the class of objects with intrinsic worth as nature prior to any human activity: primoridal nature. This point of view receives little support from philosophy in that is assumes that what is can be defended as what ought to be --- a classic logical error. Assigning intrinsic worth to the present state of Mars would argue for leaving Mars as it is. Mars' scientific value is indisputable but it is certainly true that extensive exploration followed by a careful and studied program of introducing life would yield an even greater scientific harvest. The scientific knowledge gained by studying the ways in which a biosphere could be introduced on Mars may inform us as to the preservation of the one on Earth. In the previous discussion I have assumed that Mars is presently lifeless and there is good reason to think that it is. Yet it is possible that life forms are dormant on Mars within the permafrost or have found refuge in some cryptic niche. What then for terraforming? Would it not be appropriate to then alter Mars making conditions on the planet suitable for that indigenous life so as to allow it to develop into a diverse and planetary scale biota? Along these lines I originally proposed a definition of terraforming as the purposeful alteration of another planetary environment so as to improve the chances of survival of an indigenous biology or, in the absence of any native lifeforms, to allow for habitation of most if not all terrestrial lifeforms. Will we terraform Mars? It may seem unlikely that Earthly societies would invest in such a long term project. However, if humans establish permanent research bases on Mars then orbital mechanics and travel times will dictate that these bases be as self sufficient as possible. It may well be the case that terraforming is undertaken by a group of people who consider Mars their home and for whom it is a matter of great import. What for us may seem like a flight of fancy may to them be a legacy for their children. 1. Maddox, J. Can mirrors beat the greenhouse effect? Nature 1990; 346: 311. 2. Joos, F., Sarmieto, J.L. & Siegenthaler, U. Estimates of the effect of Southern Ocean iron fertilization on atmospheric CO$_2$ concentrations. Nature 1991; 349: 772-775. 3. McKay, C.P., Toon, O.B. & Kasting, J.F. Making Mars Habitable, Nature 1991; 352: 489-496. 4. Billings, C.E. Atmosphere. In: Bioastronautics Data Book, Parker, J.F., Jr. & West, V.R. (ed.). NASA SP-3006: Washington, DC., 1973, pp 35-64. 5. Lovelock, J.E. & Allaby, M. The Greening of Mars. Warner: New York, 1984, p. 215. 6. McKay, C.P. & Stoker, C.R. The early environment and its evolution on Mars: Implications for life. Rev. Geophys. 1989; 27: 189-214. 7. Whittaker, R.H. Communities and Ecosystems, second edition, Macmillan: New York, 1975. 8. McKay, C.P. Does Mars have rights? An approach to the environmental ethics of planetary engineering. In: Moral Expertise, MacNiven, D. (ed.). Routledge: London, 1990, pp 184-197. 9. Haynes, R.H. Ecce Ecopoiesis: Playing God on Mars. In: Moral Expertise, MacNiven, D. (ed.). Routledge: London, 1990, pp 161-183. 10. Haynes, R.H. & McKay, C.P. The implantation of life on Mars: Feasibility and motivation. Adv. Space Res. 1992; 12: (4) 133-140. 11. Naess, A. The shallow and the deep, long-range ecology movement: A summary. Inquiry 1973; 16: 95-100.