Bringing Life to Mars and Mars to Life
Bringing Life to Mars, and Mars to Life
Terraforming defined • Genesis of term • Basic definition – ". . . a process of planetary engineering, specifically directed at enhancing the capacity of an extraterrestrial planetary environment to support life. The ultimate in terraforming would be to create an uncontained planetary biosphere emulating all the functions of the biosphere of the Earth–one that would be fully habitable for human beings. ” - Martyn J. Fogg • Ecopoesis – partial terraforming • Biospheres and Terran ecosystem services
Exploration/colonization • ISS vs. Terran biospheres – Materials imports and exports • Lunar and Martian outposts – Closed loop systems – In-situ resource utilization – Economic & political pressures
Earth-like Mars • • • Ecosystem size, complexity and stability Interest in terraforming Mars Day length Year length and seasonality Land surface Surface gravity
Alien Mars • • • Mars is cold (-63 o. C vs. 15 o. C) (heat budget) The air is thin (6. 4 mb) and ‘unbreathable’ (95% CO 2, N 2, Ar, O 2) No liquid water No global magnetic field
Earth and Mars history Extant life? ? ? Cold, dry planet H 2 O loss CO 2 sequestration Magnetosphere loss Techtonic shutdown Multicellular life Atmospheric O 2 Climatic cycles, Plate techtonics Core cooling Early life? ? Early life Warm, wet, anaerobic? Warm, wet, anaerobic
Mars today, re-examined • Flotilla: Pathfinder, MGS, Odyssey, Mars Express, MER Spirit & Opportunity • Polar icecaps: water ice and CO 2 • Subsurface water, Surface water(? ? ) • Implications for current water cycle • Cycles of climate change • Search for carbonates
Mars terraforming goals • • • Raised surface temperature (~ 60 o. C) Increased mass of the atmosphere Availability of liquid water Protection from UV and cosmic rays ===== Composition of atmosphere
Runaway greenhouse effect • CO 2 and H 2 O reserves • Polar CO 2 dynamics • Positive feedback mechanism to raise T and Pa • Impacts on water cycle • Unknowns: reserve levels and formats, time constants
Triggering the runaway CF 3 CF 2 CF 3, CF 3 SCF 2 CF 3, SF 6, SF 5 CF 3, SF 4(CF 3)2 • Artificial greenhouse gas production • Initial interest in CFC’s • Search for designer greenhouse gasses • Unknowns: effectiveness, lifespan, in-situ resource utilization issues
Other triggers • Change albedo of icecaps • Orbital mirrors • Cometary bombardment • Nuclear explosions in regolith
Atmospheric composition • Results of greenhouse runaway • How to oxygenate the atmosphere? – Carbon cycle – carbon sequestration needed • • Candidate primary producers for ecosystem How to build functional ecosystems? ? Time to build up O 2: 1000’s of years Nitrogen issues
Mars terraforming possibilities • Planet can be warmed and the atmosphere thickened – Easier to work outside and harvest resources • Replicating Terran biospheres is much more difficult, and will not happen soon
Environmental ethics
Discussion time
Environmental ethics concepts • • • Obligations and restrictions Moral standing and moral agents Intrinsic vs. instrumental values Anthropocentrism Biocentrism Ecocentrism
End of show
Atmospheric heat budget
Polar icecaps
Subsurface water
Recent surface water?
Polar CO 2 dynamics • Relationships between Pa, T and Pv • Stable and unstable equilibrium points
Carbon Cycle Deep ocean burial of C
Extremophiles Cyanobacteria Cryptoendoliths
Ecosystems
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