1. Terraforming Mars Fact or Fiction By: Sarah Lee PHYS-1040-007 1

2. Current Features Mars today is a cold, dry, and lifeless planet. Mars contains all the elements needed to sustain life – Water – Carbon – Oxygen (as carbon dioxide) – Nitrogen The physical aspects are similar to Earth – Gravity – Rotation Rate – Axial Tilt It has an acceptable distance to the Sun. 2

3. Beliefs It is believed that primitive Mars had a greenhouse effect. Cycling water caused volatile CO2 to form into the carbonate rock. CO2 still exists in the regolith and southern polar cap. – May be used to thicken the atmosphere to about 30% of Earth’s pressure May be able to heat the planet with an artificial induced greenhouse effect. 3

4. Atmosphere There are three reservoirs of CO2. – Atmosphere – Dry Ice in the polar caps – Gas absorbed in the soil If the polar temperature should rise, the cap will disappear and the atmosphere will be regulated by the soil reservoir. 4

5. Atmosphere Changes Atmospheric pressure would increase to 400 millibars. – Earth’s surface pressure is an average of 1000 mbs. – This would be enough pressure to eliminate the need for pressure suits. The year round climate would be above freezing for half of Mar’s surface. – Plant life could be introduced, particularly plankton. 5

6. Proposed Methods » There are three methods that seem the most promising. Use of orbital mirrors Importation of ammonia rich objects Production of artificial halocarbon gases 6

7. Orbital Mirrors Would be most practical to construct a modest mirror capable of warming limited areas by a few degrees. 7

8. Orbital Mirrors Design Would need to have a minimum radius of 125 km in order to reflect enough sunlight to raise polar regions by 5 K. If made of solar sail type aluminized mylar material, would need a density of 4 tonnes/km2 and would have a mass of 200,000 tonnes. May also be constructed from asteroidal or Martian moon materials. 120 Mwe-years of energy are required to process the materials for the reflector. Required operating altitude would need to be 214,000 km. 8

9. Orbital Mirrors Position Device would not have to orbit the planet. Solar light pressure could be made to balance the planet’s gravity. This would allow mechanism to hover as a “statite”. – Statite is an artificial satellite that uses solar sails to modify it’s orbital positioning, optimizing the use of sunlight. Power output would be focused on the polar region. 9

10. Ammonia Asteroids Ammonia is a powerful greenhouse gas. It is theorized that asteroidal objects in the outer solar system may contain large amounts of frozen ammonia. 10

11. Ammonia Asteroids Collision Course It would be easier to move an outer solar asteroid than to do so from the Main Belt. Laws of orbital mechanics state that objects farther away from the Sun orbit at a slower rate. Objects that move slower, take a smaller amount of  V to change trajectory.  V or Delta-V: It is a measure of the amount of "effort" that is needed to change from one trajectory to another by making an orbital maneuver. 11

12. Ammonia Asteroids Thrust and Time Consider an asteroid with a mass of 10 billion tonnes orbiting the Sun at 12 AU. Using Saturn’s gravity, it would require a  V of 0.3 km/s. Using a quartet of 5000 MW nuclear thermal rocket engines that would use some of the ammonia to produce an exhaust velocity, it would use 8% of asteroids material. It would take 10 years of steady thrusting, followed by 20 years of coasting until impact. 12

13. Ammonia Asteroid Impact One asteroid, upon impact, would release enough energy to be about 10 TW-years. Enough to melt 1 trillion tonnes of water. Ammonia released would raise planet temperature by 3 degrees centigrade. Would help form a shield that would mask the surface from ultraviolet radiation 13

14. Ammonia Asteroid Continuous Mission Forty such missions would double Mars’ nitrogen content. If one mission launched per year, it would take 50 years to melt enough water to cover a quarter of the planet with a 1m deep layer of water. Lifetime of an ammonia molecule on Mars is less than a century – Ammonia objects would have to be continuously imported, but with less frequency, in order to maintain supply – Continuous impacts could make Mars unsuitable for human settlement. 14

15. Ammonia Asteroids Other Options After ammonia importation begins initial greenhouse conditions, it may be possible to set up a bacterial ecology. – This would recycle the nitrogen and release ammonia back into the atmosphere. – It would eliminate the need for further impacts. 15

16. Halocarbons Amount of halocarbon gas needed to create a given temperature rise. Induced Heating (K) CFC Pressure (mbar) CFC Production (t/hr) Power Required (MWe) 50.0122631315 100.048784490 200.11241412070 300.22482924145 400.39858742933 Power that would be needed to produce required CFC’s Over a 20 year period 16

17. Halocarbons Industrialization Typical nuclear power plants used today has a power output of 1000 MWe, and provides enough energy for a medium sized American city. This would produce a trainload of refined material every day. Would require a crew of several thousand people Project budget would be several hundred billion dollars. 17

18. Halocarbons Time In several decades, Mars would transform into a warm and slightly moist planet – The air would not be breathable, but humans could wear scuba type breathing gear instead of space suits. – Would be possible to live under huge domelike inflatable tents – Hardy plan life could be introduced After a few centuries plants would produce enough oxygen for atmosphere to be breathable 18

19. Activating Hydrosphere Halocarbon gases can be produced using in-situ but will take centuries. – In-situ: Using the planets own resources as a means of production. Faster methods would be doing some violence to the planet i.e: – Use of asteroidal impacts – Thermonuclear explosives (will most likely leave the planet unacceptably radioactive) Alternative to hydrosphere activation is the use of orbiting mirrors – Triple the power from the impact of 1 10 billion tonne asteroid per year 19

20. Atmosphere Difficulties Lack of magnetic field leaves Mars atmosphere unprotected. – Has a small remnant of magnetic field at the polar regions which protect ice caps. Super wave solar winds will strip any atmosphere off. – Super waves are caused when the Sun emits two waves of different speed. One wave will crash into the other and amp it up. 20

21. Oxygenating the Planet Though the technology needed for terraforming is still speculative, it may not be impossible. Who is to say, that if the first steps are taken, that development of these technologies will not follow. Who knew that someday humans would be able to fly? 21

22. References – Technological Requirements for Terraforming Mars Technological Requirements for Terraforming Mars Robert M. Zubrin. Pioneer Astronautics. Christopher P. McKay. NASA Ames Research Center. – NASA - Consequences of Exploration: Learning from History NASA - Consequences of Exploration: Learning from History NASA's Chief Historian, Steven J. Dick – Martian Air Blown Away by Solar Super Wave By Larry O'Hanlon, Discovery News 22