Skip to main content Accessibility help
Hostname: page-component-59b7f5684b-2bkkj Total loading time: 0.353 Render date: 2022-10-03T05:24:19.296Z Has data issue: true Feature Flags: { "shouldUseShareProductTool": true, "shouldUseHypothesis": true, "isUnsiloEnabled": true, "useRatesEcommerce": false, "displayNetworkTab": true, "displayNetworkMapGraph": false, "useSa": true } hasContentIssue true

Humans Should Not Colonize Mars

Published online by Cambridge University Press:  08 February 2018



This article offers two arguments for the conclusion that we should refuse on moral grounds to establish a human presence on the surface of Mars. The first argument appeals to a principle constraining the use of invasive or destructive techniques of scientific investigation. The second appeals to a principle governing appropriate human behavior in wilderness. These arguments are prefaced by two preliminary sections. The first preliminary section argues that authors working in space ethics have good reason to shift their focus away from theory-based arguments in favor of arguments that develop in terms of pretheoretic beliefs. The second argues that of the popular justifications for sending humans to Mars only appeals to scientific curiosity can survive reflective scrutiny.

Copyright © American Philosophical Association 2018 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)


Attfield, Robin. (1981) ‘The Good of Trees’. Journal of Value Inquiry, 15, 3554.CrossRefGoogle Scholar
Barlow, Nadine. (2008) Mars: An Introduction to Its Interior, Surface and Atmosphere. Cambridge: Cambridge University Press.CrossRefGoogle Scholar
Baum, Seth. (2016) ‘The Ethics of Outer Space: A Consequentialist Perspective’. In Schwartz, and Milligan, (eds.), The Ethics of Space Exploration (New York: Springer), 109–23.CrossRefGoogle Scholar
Berry, Wendell. (1977) ‘Comments on O'Neill's Space Colonies’. In Brand (ed.), Space Colonies (Harmondsworth: Penguin).Google Scholar
Billings, Linda. (1997) ‘Frontier Days in Space: Are They Over?’. Space Policy, 13, 187–90.CrossRefGoogle Scholar
Bostrom, Nick. (2008) ‘Where Are They?’. Technology Review, 111 7277.Google Scholar
Botelho, Greg, and Watkins, Tom. (2014) ‘Ex-Boy Scout Leaders Involved in Pushing over Ancient Rock Charged’. CNN. Available at: Accessed June 3, 2017.Google Scholar
Bradbury, Ray, Clarke, Arthur, Murray, Bruce, et al. (1973) Mars and the Mind of Man. New York: Harper and Row.Google Scholar
Clarke, Arthur. (2016) ‘Sir Arthur's Quotations’. Available at: Accessed October 20, 2017.Google Scholar
Clements, David. (2009) ‘Human Spaceflight: Science or Spectacle?’. Physics World, 22, 16.CrossRefGoogle Scholar
Cockell, Charles. (2005) ‘Planetary protection: A Microbial Ethics Approach’. Space Policy, 21, 287–92.CrossRefGoogle Scholar
Conley, Catharine, and Rummel, John. (2013) ‘Appropriate Protection of Mars’. Nature Geoscience, 6, 587–88.CrossRefGoogle Scholar
Crawford, Ian. (2012) ‘Dispelling the Myth of Robotic Efficiency: Why Human Space Exploration Will Tell Us More about the Solar System than Will Robotic Exploration Alone’. Astronomy and Geophysics, 53, 2.222.26.CrossRefGoogle Scholar
Davies, Paul. (2004) ‘Life (and Death) on Mars’. New York Times. Available at: Accessed May 22, 2017.Google Scholar
Debus, André. (2005) ‘Estimation and Assessment of Mars Contamination’. Advances in Space Research, 35, 1648–53.CrossRefGoogle Scholar
de la Torre, Rosa, Sancho, Leopoldo G., Horneck, Gerda, et al. (2010) ‘Survival of Lichens and Bacteria Exposed to Outer Space Conditions: Results of the Lithopanspermia Experiments’. Icarus, 208, 735–48.CrossRefGoogle Scholar
Delgado, Laura M. (2011) ‘When Inspiration Fails to Inspire: A Change of Strategy for the US Space Program’. Space Policy, 27, 9498.CrossRefGoogle Scholar
Dyson, George. (2002) Project Orion: The True Story of the Atomic Spaceship. New York: Henry Holt.Google Scholar
Fairén, Alberto, and Schulze-Makuch, Dirk. (2013) ‘The Overprotection of Mars’. Nature Geoscience, 6, 510–11.CrossRefGoogle Scholar
Hartmann, William. (1984) ‘Space Exploration and Environmental Issues’. Environmental Ethics, 6, 227–39.CrossRefGoogle Scholar
Highfield, Roger. (2006) ‘We Must Leave Earth, Says Hawking’. The Telegraph. Available at: Accessed May 22, 2017.Google Scholar
Kminek, G., Rummel, J. D., Cockell, C. S., et al. (2010) ‘Report of the COSPAR Mars Special Regions Colloquium’. Advances in Space Research, 46, 811–29.CrossRefGoogle Scholar
Korsgaard, Christine. (2004) ‘Fellow Creatures: Kantian Ethics and Our Duties to Animals’. Tanner Lectures on Human Values, 24, 77110.Google Scholar
Lee, Keekok. (1994) ‘Awe and Humility: Intrinsic Value in Nature. Beyond an Earthbound Environmental Ethics’. Royal Institute of Philosophy Supplement, 36, 89101.CrossRefGoogle Scholar
Lester, Dan. (2013) ‘Achieving Human Presence in Space Exploration’. Presence, 22, 345–49.CrossRefGoogle Scholar
Lewis, John. (1997) Mining the Sky: Untold Riches from the Asteroids, Comets, and Planets. New York: Basic Books.Google Scholar
Limerick, Patricia. (1992) ‘Imagined Frontiers: Westward Expansion and the Future of the Space Program’. In Byerly (ed.), Space Policy Alternatives (Boulder: Westview Press), 249–62.Google Scholar
McArthur, Dan, and Boran, Idil. (2004) ‘Agent-Centered Restrictions and the Ethics of Space Exploration’. Journal of Social Philosophy, 35, 148–63.CrossRefGoogle Scholar
McKay, Christopher. (2011) ‘The Search for Life in Our Solar System and the Implications for Science and Society’. Philosophical Transactions of the Royal Society of London, 369, 594606.CrossRefGoogle ScholarPubMed
Milligan, Tony. (2015) Nobody Owns the Moon: The Ethics of Space Exploitation. Jefferson: McFarland.Google Scholar
Milligan, Tony. (2016) ‘Space Ethics Without Foundations’. In Schwartz, and Milligan, (eds.), The Ethics of Space Exploration (New York: Springer), 125–34.CrossRefGoogle Scholar
Munévar, Gonzalo. (2014) ‘Space Exploration and Human Survival’. Space Policy, 30, 197201.CrossRefGoogle Scholar
NASA. Jet Propulsion Laboratory. ‘Planetary Protection: Mars Science Laboratory’. Available at: Accessed June 3, 2017.Google Scholar
Neuberger, Katja, Lux-Endrich, Astrid, Panitz, Corinna, and Horneck, Gerda. (2015) ‘Survival of Spores of Trichoderma Longibrachiatum in Space: Data from the Space Experiment SPORES on EXPOSE-R’. International Journal of Astrobiology, 14, 129135.CrossRefGoogle Scholar
Onofri, Silvano, Jean-Pierre de, Vera, Zucconi, Laura, et al. (2015) ‘Survival of Antarctic Cryptoendolithic Fungi in Simulated Martian Conditions On Board the International Space Station’. Astrobiology, 15, 1052–59.CrossRefGoogle ScholarPubMed
Robinson, Edward. (2014) ‘For Libertarian Utopia, Float Away on ‘Startup’ Nation’. Bloomberg Markets. Available at: Accessed May 20, 2017.Google Scholar
Rummel, John, Stabekis, P. D., DeVincenzi, D. L., and Barengoltz, J. B.. (2002) ‘COSPAR's Planetary Protection Policy: A Consolidated Draft’. Advances in Space Research, 30, 1567–71.CrossRefGoogle Scholar
Sagan, Carl. (1994) Pale Blue Dot: A Vision of the Human Future in Space. New York: Random House.Google Scholar
Sancho, Leopoldo G., de la Torre, Rosa, Horneck, Gerda, et al. (2007) ‘Lichens Survive in Space: Results from the 2005 LICHENS Experiment’. Astrobiology, 7, 443–54.CrossRefGoogle ScholarPubMed
Scherer, Donald. (1988) ‘A Disentropic Ethic’. The Monist, 71, 332.CrossRefGoogle Scholar
Schwartz, James. (2011) ‘Our Moral Obligation to Support Space Exploration’. Environmental Ethics, 33, 6788.CrossRefGoogle Scholar
Schwartz, James. (2014) ‘Prioritizing Scientific Exploration: A Comparison of the Ethical Justifications for Space Development and for Space Science’. Space Policy, 30, 202208.CrossRefGoogle Scholar
Schwartz, James. (2016) ‘On the Methodology of Space Ethics’. In Schwartz, and Milligan, (eds.), The Ethics of Space Exploration (New York: Springer), 93107.CrossRefGoogle Scholar
Schwartz, James. (2017) ‘Myth-Free Space Advocacy, Part I: The Myth of Innate Exploratory and Migratory Urges’. Acta Astronautica, 137, 450–60.CrossRefGoogle Scholar
Sheppard, Kathleen. (2013) The Life of Margaret Alice Murray: A Woman's Work in Archaeology. Plymouth: Lexington Books.Google Scholar
Singer, Peter. (1972) ‘Famine, Affluence, and Morality’. Philosophy and Public Affairs, 1, 229–43.Google Scholar
Smith, Kelly. (2014) ‘Manifest Complexity: A Foundational Ethic for Astrobiology?Space Policy, 30, 209–14.CrossRefGoogle Scholar
Smith, Kelly. (2016) ‘The Curious Case of the Martian Microbes: Mariomania, Intrinsic Value and the Prime Directive’. In Schwartz, and Milligan, (eds.), The Ethics of Space Exploration (New York: Springer), 195208.CrossRefGoogle Scholar
Sparrow, Robert. (1999) ‘The Ethics of Terraforming’. Environmental Ethics, 21, 227–45.CrossRefGoogle Scholar
Taylor, Adam. (2017) ‘The UAE's Ambitious Plan to Build a New City — on Mars’. Washington Post. Available at: Accessed May 22, 2017.Google Scholar
Thomas, Cathy Booth. (2007) ‘The Space Cowboys’. Time, 169, 5258.Google Scholar
Thomson, Judith Jarvis. (1971) ‘A Defense of Abortion’. Philosophy and Public Affairs, 1, 4766.Google Scholar
Twilley, Nicola. (2015) ‘Meet the Martians’. The New Yorker. Available at: Accessed June 3, 2017.Google Scholar
Urban, Tim. (2015) ‘How (and Why) SpaceX Will Colonize Mars’. Wait But Why. Available at: Accessed May 10, 2017.Google Scholar
Weinberg, Steven. (2013) ‘Response: Against Manned Space Flight Programs’. Space Policy, 29, 229–30.CrossRefGoogle Scholar
West, Michael, and Clarke, Jonathan. (2010) ‘Potential Martian Mineral Resources: Mechanisms and Terrestrial Analogues’. Planetary and Space Science, 58, 574–82.CrossRefGoogle Scholar
Wilks, Anna Frammartino. (2016) ‘Kantian Foundations for a Cosmocentric Ethic’. In Schwartz, and Milligan, (eds.), The Ethics of Space Exploration (New York: Springer), 181–94.CrossRefGoogle Scholar
Wilson, Jim. (2016) ‘Journey to Mars Overview’. NASA. Available at: Accessed May 22, 2017.Google Scholar
Yárnoz, D. García, Sanchez, J. P., and McInnes, C. R.. (2013) ‘Easily Retrievable Objects among the NEO Population’. Celestial Mechanics and Dynamical Astronomy, 116, 367–88.CrossRefGoogle Scholar
York, Paul Francis. (2002) ‘The Ethics of Terraforming’. Philosophy Now, 38, 69.Google Scholar
York, Paul Francis. (2005) ‘Respect for the World: Universal Ethics and the Morality of Terraforming’. PhD. diss., University of Queensland.Google Scholar
York, Richard. (2005) ‘Toward a Martian Land Ethic’. Human Ecology Review, 12, 72.Google Scholar
Zimmer, Ben. (2010) ‘Be Careful What You Plan For’. Radiolab. Available at: Accessed June 6, 2017.Google Scholar
Zubrin, Robert. (2012) The Case For Mars. New York: Simon and Schuster.Google Scholar
Cited by

Save article to Kindle

To save this article to your Kindle, first ensure is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.

Note you can select to save to either the or variations. ‘’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Humans Should Not Colonize Mars
Available formats

Save article to Dropbox

To save this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Dropbox account. Find out more about saving content to Dropbox.

Humans Should Not Colonize Mars
Available formats

Save article to Google Drive

To save this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Google Drive account. Find out more about saving content to Google Drive.

Humans Should Not Colonize Mars
Available formats

Reply to: Submit a response

Please enter your response.

Your details

Please enter a valid email address.

Conflicting interests

Do you have any conflicting interests? *