Mars Society

From Wikipedia, the free encyclopedia

 

Mars Society

Founded	August 1998
Type	Nonprofit corporation with §501(c)(3) federal income tax exemption.
Legal status	The Mars Society is a "public charity" and is eligible to receive tax-deductible charitable contributions.
Focus	Space advocacy and Manned mission to Mars
Location	Lakewood, Colorado, United States of America
Area served	U.S.A-based internationally active
Key people	Board of Directors: Robert Zubrin (President) James Heiser Officers & Staff: Lucinda Offer, Executive Director Michael Stoltz, VP, Development, & Dir. Media & Public Relations Nicole Willett, Dir., Educational Outreach Florence Maisch, Dir., Volunteers Shannon Rupert, Dir. Program Manager, MDRS Joseph Palaia, Mission Director, FMARS Kevin Sloan, Dir., University Rover Challenge (URC) James Burk, Webmaster & IT Director Carie Fay, Dir., Administration Frank Crossman, Chief Archivist
Website	http://www.marssociety.org

The Mars Society is an American worldwide volunteer-driven space-advocacy non-profit organization dedicated to promoting the human exploration and settlement of the planet Mars. Inspired by "The Case for Mars" conferences which were hosted by The Mars Underground at the University of Colorado Boulder, the Mars Society was established by Dr. Robert Zubrin and others in 1998 with the goal of educating the public, the media and government on the benefits of exploring Mars, the importance of planning for a humans-to-Mars mission in the coming decades and the need to create a permanent human presence on the Red Planet.

History

Mars Society, Inc. was formally established in September 1997 under the Colorado Non-Profit Corporation Act. In August 1998 more than 700 delegates – astronomers, scientists, engineers, astronauts, entrepreneurs, educators, students and space enthusiasts – attended a week-end of talks and presentations from leading Mars exploration advocates. Since then, the Mars Society, guided by its steering committee, has grown to over 5,000 members and some 6,000 associate supporters across more than 50 countries around the world. Members of the Mars Society are from all walks of life and actively work to promote the ideals of space exploration and the opportunities for exploring the Red Planet. In 2017 the Marspedia encyclopedia became an official project of the Mars Society.

Mars Society's purpose, mission and goals

The Mars Society's goals aren't purely theoretical. Its aim is to show that Mars is an achievable goal through a practical series of technical and other projects, including:

• Further development of the Mars Direct mission plan to send humans to Mars
• The Mars Analog Research Station Program (MARS) – analogues of possible future Mars habitation units, located in Mars-like environments. Established stations include the Flashline Mars Arctic Research Station (FMARS) and the Mars Desert Research Station (MDRS)
• The University Rover Challenge – a competition to design a pressurized rover vehicle that could be used on Mars that was won by the Michigan Mars Rover Team.
• The MarsVR Program – a mulit-phase effort to built virtual reality tools to support the human exploration of Mars, and train the crewmembers at the Mars Desert Research Station.
• The Mars Gravity Biosatellite - a program to design, build, and launch a satellite rotated to artificially provide partial gravity of 0.38g, equivalent to that of Mars, and hosting a small population of mice, to study the health effects of partial gravity, as opposed to zero gravity; this originated as a Mars Society initiative and is now supported by the YourNameIntoSpace web portal
• The Mars balloon mission ARCHIMEDES, due to launch in 2018 (conducted by the German Chapter of Mars Society)
• Tempo3 The Tethered Experiment for Mars inter-Planetary Operations, a CubeSat based satellite that will demonstrate artificial gravity generation using two tethered masses

In addition, the Society:

• gives talks and presentations on Mars Direct to schools, colleges, universities, professional bodies and the general public
• promotes the teaching of science, astronomy and spaceflight-related subjects in schools
• campaigns for greater investment on the part of individual countries in space research and development
• hosts the largest annual conferences on Mars exploration in the United States, Europe and Australia
• actively supports NASA, ESA and other space agencies in their on-going exploration of Mars

The current board of directors of the Mars Society includes Robert Zubrin (chairman) and James Heiser.

Notable members of its steering committee include Buzz Aldrin and Peter H. Smith.

Notable former members of the board of directors or steering committee of the Mars Society include Kim Stanley Robinson, Michael D. Griffin, Christopher McKay, and Pascal Lee.

The Society is an organization member of the Alliance for Space Development.

North American Chapters of the Mars Society

The Mars Society has chapters in the U.S. and around the world. Many of these chapters undertake scientific, engineering and political initiatives to further the Mars Society's goals. Some accomplishments of Mars Society chapters are listed below:

Canada

Mars Society of Canada:

• hosted the Third International Mars Society Convention in 2000 (Toronto)
• organized a month-long multi-national research expedition (known as Expedition One) to the Mars Desert Research Station in the Utah desert in 2003
• organized a second multi-national research expedition (known as Expedition Two) in the Australian outback in 2004
• organized a series of training expeditions (beginning with Expedition Alpha, Beta etc.)

United States

California

Northern California Chapter of the Mars Society:

• hosted the Fourth International Mars Society Convention in 2001 (Stanford University)
• raised over $100,000 for the Mars Society hosting a fundraiser banquet with James Cameron, May 5, 2001
• provided Mission Support services for crews at the Mars Desert Research Station starting in 2002

San Diego

The Mars Society - San Diego:

• provides Crewmembers and Mission Support services for the Mars Desert Research Station (MDRS) and the Flashline Mars Arctic Research Station (FMARS) since 2002
• TMS-SD provides public outreach events to classrooms, libraries, museums and other organizations throughout the Southern California region with seven different multimedia programs: "Invasion from Earth - The Robotic Exploration of Mars"; "Mars Exploration Rovers - Year 4"; "Mars on Earth - The Adventures of Space Pioneers in the Utah Desert"; "Mars on Earth - The Adventures of Space Pioneers in the Canadian Arctic: "Humans to Mars - How We'll Get There"; "A Close Look at Mars"; and "Mars in the Movies"
• TMS-SD offers a 1/4-scale radio controlled Mars Exploration Rover with wireless video that children (of all ages) can operate
• holds monthly chapter meetings, as well as special program events throughout the year
• hosts a monthly Mars Movie Night in conjunction with The Mars Movie Guide

Texas

Dallas Chapter of the Mars Society:

• hosted the Mars Track of the National Space Society's International Space Development Conference in 2007
• Planning Publicizing, and Politicking a vision of Mars colonization in the Dallas area and beyond.

Washington

Mars Society Seattle (formerly known as Mars Society Puget Sound):

• Hosted MarsFest with Seattle's Museum of Flight in 1999 (Polar Lander), 2007 (Phoenix), and 2012 (Curiosity).
• Staffed outreach table at local events: NSTA conference, Yuri's Night, Norwescon, Rustycon, AIAA, and others.
• Speaker series (co-sponsored with NSS Seattle) every first Sunday of the month at 7pm in the Red Barn classroom at the Museum of Flight.
• Website development for the Mars Society in the early days, helped set up chapters.marssociety.org and initial task force websites.

European Chapters of the Mars Society

Austria

The ASF (Österreichisches Weltraum Forum, OeWF) is a national network for aerospace and space enthusiasts, being the Austrian chapter of the Mars Society. The Forum serves as a communication platform between the space sector and the public; it is embedded in a global network of specialists from the space industry, research and policy. Hence, the OeWF facilitates a strengthening of the national space sector through enhancing the public visibility of space activities, technical workshops, and conferences as well as Forum-related projects.

Their research focus is Mars Analogue Research, e.g. the AustroMars mission with roughly 130 volunteers supporting a mission simulation at the Mars Desert Research Station (MDRS) and the ongoing PolAres, a multi-year research program which encompass the development of a Mars analogue rover system and a novel spacesuit prototype dubbed "Aouda.X", culminating in an arctic expedition in 2011.

The Forum has a small, but a highly active pool of professional members contributing to space endeavors, mostly in cooperation with other nations as well as international space organizations. The spectrum of their activities ranges from simple classroom presentation to 15.000-visitors space exhibitions, from expert reports for the Austrian Federal Ministry for Technology to space technology transfer activities for terrestrial applications.

France

The Mars Society French chapter (Association Planète Mars) was established in 1999 as "Association Planète Mars", a non-profit organization with its headquarters in Paris. Its founder and president is Richard Heidmann, a space propulsion engineer, who participated in the founding convention of the Mars Society in August 1998 and is a member of the Mars Society Steering Committee.

While fully supporting the ideas and actions of the Mars Society, it considers that those must be adapted to the specific cultural and political context of France and Europe. The main activities of Association Planète Mars are devoted to public communication, through conferences, exhibits, events, media appearances (TV, radio, magazines...). It also acts occasionally as an adviser for journalists or film makers.

Whenever possible, it cooperates with other associations or science outreach organisms, which permits to reinforce its action and reach a wider public.

Association Planète Mars seeks to interest younger people: 25% of its paid members are under the age of 25. It aims to encourage Mars-related projects to be undertaken by engineering students. The association also encourages the formation of working groups on miscellaneous topics. Today, three groups are active, respectively on mission safety, Martian architecture and medical aspects. It has participated in several MDRS and FMARS missions, including a prototype of a "Cliff Exploration Vehicle".

Another major field of action is lobbying, aiming at both political and institutional groups, in France and at the European level (European Council, ESA). In doing so, it relies on the networks established by some of its managers. On the occasion of most critical events, the association publishes political documents to support its views, which are distributed both to opinion formers and to the press. This has been the case in June 2004, in the wake of the US Space Exploration Initiative, and in September 2008 in preparation of the ESA ministerial council.

Germany

The German Chapter of the Mars Society (Mars Society Deutschland e.V. | eingetragener Verein | - MSD) was founded in 2001 based on the Founding Declaration of the Mars Society of the USA from 1998 and has about 230 members. The MSD is registered in Germany as a non-profit association (gemeinnütziger Verein). Registered members pay a yearly membership fee of 60 Euro. However, students and firms pay a different fee. The activities of the MSD are focused on technical-scientific projects such as the Mars Balloon Probe ARCHIMEDES as well as on all Mars exploration and general manned space matters. The main means of communication with members and the general public is the MSD Website with information on the ARCHIMEDES project, publications on Mars and other space subjects, the regular news, which can be commented by visitors of the website, the Space Forum and informative meetings.

The MSD Board comprises five members. Since June 2009 its president is the Space Physicist Dr. Michael Danielides. The development of ARCHIMEDES is led by Dipl.Ing. Hannes Griebel, who is also a member of the MSD Board and prepares his doctorate thesis on ARCHIMEDES.
ARCHIMEDES is presently under development and the major project of the MSD since 2001. Starting in 2006, flight tests have been undertaken for testing the innovative balloon system in the low-gravity environment. Test carriers were so far the Airbus A300 for short duration parabolic flights and the sounding rocket test campaigns REXUS3-REGINA and REXUS4-MIRIAM for longer duration flight tests under free space conditions. Further flights tests are planned for the coming years (e.g. MIRIAM II) with the objective of qualifying ARCHIMEDES for its Mars mission by 2018. ARCHIMEDES will be carried to Mars on board an AMSAT Mars Probe or a similar satellite. ARCHIMEDES is developed by the MSD with the support of the Bundeswehr University Munich, of the IABG in Ottobrunn, the DLR-MORABA for rocket flight opportunities, other universities, and several industrial companies supporting specific technical areas.

Netherlands

The Mars Society Netherlands chapter was wound up in 2011. The board and members moved over to a new Mars-oriented organisation, Explore Mars.

Poland

The Polish Mars society (Mars Society Polska (MSP)) is actively participating in the creation of the Polish space industry. Since this sector is still developing, the organization is taking the opportunity to provide a strong Mars-related element for the years to come. Poland was the last member state of the EU to sign the cooperation agreement with ESA. Most projects in Poland currently focus on satellite technology, so MSP is the only leading organization promoting exploration and manned spaceflight. Besides private sponsors, it relies on resources obtained from the Ministry of Science and Higher Education and local authorities, proposing projects to be undertaken with local communities and thus engaging with the general public.

MSP's first project was the Polish MPV (pressurized rover) design, for which some hardware was produced. This enabled development of the Polish Mars Society itself, together with a number of educational activities for Polish schools. This was followed by the joint organization of the Polish edition of the Red Rover Goes to Mars contest and organization of a Mars colonization negotiation game (Columbia Memorial Negotiations). In 2007 MSP organized the first Mars Festival, a two-day event which drew 600 visitors, with Discovery Channel as the main sponsor. Mars Festival 2008 was smaller due to the efforts being made in other projects, particularly the Polish URC rover, named Skarabeusz.

The flagship MSP project is the Polish Martian habitat, based on a design by Janek Kozicki. It has three inflatable modules attached and a usable surface of 900 m². The habitat is to be located close to a large town, meaning that beyond its role as a test site, largely for materials and design, it will be accessible to the wider public and media.

MSP has established a constant presence in the mainstream Polish media and is working on a documentary about itself. It is also developing software projects, IT systems for the future martian habitat, with a Virtual Mars Base and remote access. Jan Kotlarz of MSP has created RODM software for the modeling of the Martian surface based on high-resolution photographs from Mars Reconnaissance Orbiter. RODM is currently being tested by NASA and ESA.

Switzerland

The Mars Society Switzerland ("MSS") was founded in February 2010. It covers the French and German speaking parts of Switzerland. It keeps close links with the French branch ("association planète Mars", see above). Its aim is to convince the Swiss public of the interest and feasibility of the Martian exploration with inhabited flights through the Mars direct concept such as described by Robert Zubrin. It wants to gather around the scientists working on Mars in Switzerland, all people who share their interest on the matter.

In November 2010, MSS participated to the 8th Swiss Geoscience Meeting which was the opportunity to discuss the main topics related to Mars geology, the making of the planet, the role of water and the atmosphere.

In 2011 (September 30 until October 2), MSS held the 11th European Mars Convention ("EMC11") in the frame of the University of Neuchâtel. Through 24 presentations and two debates with major Swiss media, this convention covered all subjects related to Mars exploration; from astronautics to architecture, including the study of geology which remains its key objective.

On September 10, 2012, in the Natural History Museum Bern ("NHMB"), it held a conference on the theme "Searching for Life on Mars". The conference was centered upon a presentation by Professor André Maeder (a well-known astrophysicist at the University of Geneva) following the publishing of his book "L'unique Terre habitée?" (Favre editions). Another presentation was made by Dr. Beda Hofmann, Head of the Earth Science Dept. of the NHMB. He showed and commented photos of primitive forms of life which he gathered to serve as references for the observations to be made by the ESA ExoMars mission (to be launched in 2018). Pierre Brisson, president of the Mars Society Switzerland introduced the conference, speaking about the instruments aboard Curiosity and the targets of exploration of the rover.

In October (12th till 14th) The Mars Society Switzerland participated to the 12th EMC ("EMC12") in Neubiberg, Germany (University of the German Armed Forces, near Münich). In this frame, Pierre Brisson discussed the past possibility of an Ocean in the Northern Lowlands of the planet.

A key event of the year 2013 (March 26), was a conference organized with "Club 44" in La Chaux de Fonds, during which Professor Michel Cabane, LATMOS and co-PI of the SAM Instruments aboard Curiosity, presented the findings of his instruments dedicated to the study of the molecular and atomic compositions of the rocks and atmosphere of the planet Mars.

United Kingdom

The Mars Society UK is the oldest Mars Society outside the United States. It held its first public meeting on July 4, 1998, in London. Professor Colin Pillinger, head of the Beagle 2 project, was the Guest Speaker, and the event marked the first time Beagle 2 had been presented to the general public in the UK. From 1998 through to 2003, the Mars society UK (MSUK) continued to support Beagle 2, providing numerous public events at which members of the Beagle 2 project team could speak, and the Beagle 2 model be displayed.

Highlights of the MSUK's history include:

• It hosted the first Mars Society European Leaders Meeting, with representatives from France, Germany, Poland, Spain and the Netherlands.
• The first UK Mars Day, attended by some 200 members of the public took place in 2002. It was covered by all the UK's leading television media (BBC, ITN, Sky News).
• In 2003, it had white papers accepted and published by the UK government as a part of a review of UK Space Policy. It also actively lobbied for UK involvement in human spaceflight endeavours.
• Since 2006 it helped establish the Sir Arthur Clarke Award, the most prodigious award given in the United Kingdom for contribution in all field of space research and exploration. it also continued to provide consultation and white papers on the UK's changing space policy and helped determine the UK government's decision to actively engage in human spaceflight activities from 2010.
• It is currently engaged in a further UK space policy review aimed at determining whether the UK requires a dedicated space agency.

More recently, the MSUK had been allied with attempts to initiate a formally recognized and fully founded UK Space Conference (UKSC) with the first such event being held in April 2009.

Asian Chapters of the Mars Society

India

The Mars Society India chapter (MSI) was founded in January 2012 by Dhruv Joshi, an alumnus of the Indian Institute of Technology Bombay. Dhruv Joshi was inspired to set up the chapter in India after he attended a presentation by Mars society Switzerland chapter; during his visit to Switzerland. MSI was launched on March 2, 2012 at Mumbai, with collaboration from Nehru center (Planetarium) and students of Indian Institute of Technology - Bombay (IIT-B). MSI endeavors to set a platform for bringing immense talent pool of Indian students to the forefront and achieve country's ambitious space missions.

Bangladesh

Mars Society Bangladesh chapter was found in 2016. A group of 40 students and three teams from Bangladesh participated in 2016 University Rover Challenge (URC 2016) powered by Mars Society, held in June 2016 at Utah, USA.

Oceania Chapters of the Mars Society

Australia

There is a chapter in Australia, with branches in Australian Capital Territory (ACT), New South Wales (NSW), Northern Territory, Queensland, South Australia, Tasmania, Victoria, and Western Australia. The main goals for Mars Society Australia are to support government funded programs geared towards exploring Mars and reach out to the public about both exploring Mars and the importance of studying planetary sciences and engineering.

New Zealand

The NZ Mars Society has the same list of goals as Australia. In an effort to help put people on Mars, they plan to have their members test surface exploration strategies and technologies in locations dedicated to Mars analogue.  One of these Mars analogue locations is Mars Desert Research Station in Utah. 

Martian soil

From Wikipedia, the free encyclopedia

 

Curiosity's view of Martian soil and boulders after crossing the "Dingo Gap" sand dune (February 9, 2014; raw color).

Martian soil is the fine regolith found on the surface of Mars. Its properties can differ significantly from those of terrestrial soil. The term Martian soil typically refers to the finer fraction of regolith. On Earth, the term "soil" usually includes organic content. In contrast, planetary scientists adopt a functional definition of soil to distinguish it from rocks. Rocks generally refer to 10 cm scale and larger materials (e.g., fragments, breccia, and exposed outcrops) with high thermal inertia, with areal fractions consistent with the Viking Infrared Thermal Mapper (IRTM) data, and immobile under current aeolian conditions. Consequently, rocks classify as grains exceeding the size of cobbles on the Wentworth scale.

This approach enables agreement across Martian remote sensing methods that span the electromagnetic spectrum from gamma to radio waves. ‘‘Soil’’ refers to all other, typically unconsolidated, material including those sufficiently fine-grained to be mobilized by wind.^[2] Soil consequently encompasses a variety of regolith components identified at landing sites. Typical examples include: bedform armor, clasts, concretions, drift, dust, rocky fragments, and sand. The functional definition reinforces a recently proposed genetic definition of soil on terrestrial bodies (including asteroids and satellites) as an unconsolidated and chemically weathered surficial layer of fine-grained mineral or organic material exceeding centimeter scale thickness, with or without coarse elements and cemented portions.

Martian dust generally connotes even finer materials than Martian soil, the fraction which is less than 30 micrometres in diameter. Disagreement over the significance of soil's definition arises due to the lack of an integrated concept of soil in the literature. The pragmatic definition "medium for plant growth" has been commonly adopted in the planetary science community but a more complex definition describes soil as "(bio)geochemically/physically altered material at the surface of a planetary body that encompasses surficial extraterrestrial telluric deposits." This definition emphasizes that soil is a body that retains information about its environmental history and that does not need the presence of life to form.

Observations

Comparison of Soils on Mars - Samples by Curiosity rover, Opportunity rover, Spirit rover (December 3, 2012).

 

First use of the Curiosity rover scooper as it sifts a load of sand at "Rocknest" (October 7, 2012).

Mars is covered with vast expanses of sand and dust and its surface is littered with rocks and boulders. The dust is occasionally picked up in vast planet-wide dust storms. Mars dust is very fine, and enough remains suspended in the atmosphere to give the sky a reddish hue. The reddish hue is due to rusting iron minerals presumably formed a few billion years ago when Mars was warm and wet, but now that Mars is cold and dry, modern rusting may be due to a superoxide that forms on minerals exposed to ultraviolet rays in sunlight. The sand is believed to move only slowly in the Martian winds due to the very low density of the atmosphere in the present epoch. In the past, liquid water flowing in gullies and river valleys may have shaped the Martian regolith. Mars researchers are studying whether groundwater sapping is shaping the Martian regolith in the present epoch, and whether carbon dioxide hydrates exist on Mars and play a role.

First X-ray diffraction view of Martian soil - CheMin analysis reveals feldspar, pyroxenes, olivine and more (Curiosity rover at "Rocknest", October 17, 2012).

 

It is believed that large quantities of water and carbon dioxide ices remain frozen within the regolith in the equatorial parts of Mars and on its surface at higher latitudes. Water contents of Martian regolith range from <2 a="" by="" href="https://en.wikipedia.org/wiki/Olivine" more="" of="" presence="" than.="" the="" title="Olivine" to="" weight="">olivine
, which is an easily weatherable primary mineral, has been interpreted to mean that physical rather than chemical weathering processes currently dominate on Mars. High concentrations of ice in soils are thought to be the cause of accelerated soil creep, which forms the rounded "softened terrain" characteristic of the Martian midlatitudes.
In June, 2008, the Phoenix Lander returned data showing Martian soil to be slightly alkaline and containing vital nutrients such as magnesium, sodium, potassium and chloride, all of which are necessary for living organisms to grow. Scientists compared the soil near Mars' north pole to that of backyard gardens on Earth, and concluded that it could be suitable for growth of plants. However, in August, 2008, the Phoenix Lander conducted simple chemistry experiments, mixing water from Earth with Martian soil in an attempt to test its pH, and discovered traces of the salt perchlorate, while also confirming many scientists' theories that the Martian surface was considerably basic, measuring at 8.3. The presence of the perchlorate, if confirmed, would make Martian soil more exotic than previously believed. Further testing is necessary to eliminate the possibility of the perchlorate readings being caused by terrestrial sources, which may have migrated from the spacecraft either into samples or the instrumentation.

"Sutton Inlier" soil on Mars - target of ChemCam's laser - Curiosity rover (May 11, 2013).

While our understanding of Martian soils is extremely rudimentary, their diversity may raise the question of how we might compare them with our Earth-based soils. Applying an Earth-based system is largely debatable but a simple option is to distinguish the (largely) biotic Earth from the abiotic Solar System, and include all non-Earth soils in a new World Reference Base for Soil Resources Reference Group or USDA soil taxonomy Order, which might be tentatively called Astrosols.

On October 17, 2012 (Curiosity rover at "Rocknest"), the first X-ray diffraction analysis of Martian soil was performed. The results revealed the presence of several minerals, including feldspar, pyroxenes and olivine, and suggested that the Martian soil in the sample was similar to the "weathered basaltic soils" of Hawaiian volcanoes. Hawaiian volcanic ash has been used as Martian regolith simulant by researchers since 1998.

In December 2012, scientists working on the Mars Science Laboratory mission announced that an extensive soil analysis of Martian soil performed by the Curiosity rover showed evidence of water molecules, sulphur and chlorine, as well as hints of organic compounds. However, terrestrial contamination, as the source of the organic compounds, could not be ruled out.

On September 26, 2013, NASA scientists reported the Mars Curiosity rover detected "abundant, easily accessible" water (1.5 to 3 weight percent) in soil samples at the Rocknest region of Aeolis Palus in Gale Crater. In addition, NASA reported that the Curiosity rover found two principal soil types: a fine-grained mafic type and a locally derived, coarse-grained felsic type. The mafic type, similar to other martian soils and martian dust, was associated with hydration of the amorphous phases of the soil. Also, perchlorates, the presence of which may make detection of life-related organic molecules difficult, were found at the Curiosity rover landing site (and earlier at the more polar site of the Phoenix lander) suggesting a "global distribution of these salts". NASA also reported that Jake M rock, a rock encountered by Curiosity on the way to Glenelg, was a mugearite and very similar to terrestrial mugearite rocks.

Atmospheric dust

Martian Dust Devil - in Amazonis Planitia (April 10, 2001).

 

Dust storms on Mars.

 

June 6, 2018.

 

November 25, 2012

 

November 18, 2012

Locations of Opportunity and Curiosity rovers are noted (MRO).
 

Similarly sized dust will settle from the thinner Martian atmosphere sooner than it would on Earth. For example, the dust suspended by the 2001 global dust storms on Mars only remained in the Martian atmosphere for 0.6 years, while the dust from Mt. Pinatubo took about 2 years to settle. However, under current Martian conditions, the mass movements involved are generally much smaller than on Earth. Even the 2001 global dust storms on Mars moved only the equivalent of a very thin dust layer – about 3 µm thick if deposited with uniform thickness between 58° north and south of the equator. Dust deposition at the two rover sites has proceeded at a rate of about the thickness of a grain every 100 sols.

The difference in the concentration of dust in Earth's atmosphere and that of Mars stems from a key factor. On Earth, dust that leaves atmospheric suspension usually gets aggregated into larger particles through the action of soil moisture or gets suspended in oceanic waters. It helps that most of earth's surface is covered by liquid water. Neither process occurs on Mars, leaving deposited dust available for suspension back into the Martian atmosphere. In fact, the composition of Martian atmospheric dust – very similar to surface dust – as observed by the Mars Global Surveyor Thermal Emission Spectrometer, may be volumetrically dominated by composites of plagioclase feldspar and zeolite which can be mechanically derived from Martian basaltic rocks without chemical alteration. Observations of the Mars Exploration Rovers’ magnetic dust traps suggest that about 45% of the elemental iron in atmospheric dust is maximally (3+) oxidized and that nearly half exists in titanomagnetite, both consistent with mechanical derivation of dust with aqueous alteration limited to just thin films of water. Collectively, these observations support the absence of water-driven dust aggregation processes on Mars. Furthermore, wind activity dominates the surface of Mars at present, and the abundant dune fields of Mars can easily yield particles into atmospheric suspension through effects such as larger grains disaggregating fine particles through collisions.

The Martian atmospheric dust particles are generally 3 µm in diameter. It is important to note that while the atmosphere of Mars is thinner, Mars also has a lower gravitational acceleration, so the size of particles that will remain in suspension cannot be estimated with atmospheric thickness alone. Electrostatic and van der Waals forces acting among fine particles introduce additional complexities to calculations. Rigorous modeling of all relevant variables suggests that 3 µm diameter particles can remain in suspension indefinitely at most wind speeds, while particles as large as 20 µm diameter can enter suspension from rest at surface wind turbulence as low as 2 ms⁻¹ or remain in suspension at 0.8 ms⁻¹.

In July 2018, researchers reported that the largest single source of dust on the planet Mars comes from the Medusae Fossae Formation.

Mars (before/after) dust storm (July 2018)

 

Mars without a dust storm in June 2001 (on left) and with a

global dust storm in July 2001 (on right), as seen by Mars

Global Surveyor

 

Namib sand dune (downwind side) on Mars
(Curiosity rover; December 17, 2015).

Gallery

• 

  Martian sand and boulders photographed by NASA's Mars Exploration Rover Spirit (April 13, 2006).
  
  
• 

  "Hottah" rock outcrop (close-up; 3D) (September 12, 2012).
  
  
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  "Rocknest" sand on Mars – scoffmark made by the Curiosity rover (MAHLI, October 4, 2012).
  
  
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  "Rocknest 3" rock on Mars – as viewed by the MastCam on Curiosity (October 5, 2012).
  
  
• 

  Tracks of the Curiosity rover in the sands of "Hidden Valley" (August 4, 2014).
  
  
• 

  Wheel of the Curiosity rover partially submerged in sand at Hidden Valley (August 6, 2014).
  

• 

  Sand moving on Mars – as viewed by Curiosity (January 23, 2017).
  
  
• 

  Blue dune on Mars
  (January 24, 2018).
  
  
• 

  Blue dune on Mars>
  (Enhanced color; January 24, 2018)
  

This Is Why Dark Energy Must Exist, Despite Recent Reports To The Contrary

Ethan Siegel Senior Contributor

Original link:  https://www.forbes.com/sites/startswithabang/2018/09/11/this-is-why-dark-energy-must-exist-despite-recent-reports-to-the-contrary/#47d9b1d02356

The different possible fates of the Universe, with our actual, accelerating fate shown at the right. After enough time goes by, the acceleration will leave every bound galactic or supergalactic structure completely isolated in the Universe, as all the other structures accelerate irrevocably away. We can only look to the past to infer dark energy's presence. NASA & ESA

It was a mere 20 years ago that our picture of the Universe got a stunning revision. We all knew our Universe was expanding, that it was full of matter and radiation, and that most of the matter out there couldn't be made of the same, normal stuff (atoms) that we were most familiar with. We were trying to determine, based on how the Universe was expanding, what our fate was: would we recollapse, expand forever, or be right on the border between the two?

Distant supernovae of a specific type were the tool we would use to decide. In 1998, enough data had come in that two independent teams released the surprising results: the Universe would not only expand forever, but the expansion was accelerating.

One of the best data sets of available supernovae, collected over a period of approximately 20 years, with their uncertainties shown in the error bars. This was the first line of evidence that robustly indicated the accelerated expansion of the Universe. Miguel Quartin, Valerio Marra and Luca Amendola, Phys. Rev. D (2013)

In order for this to be true, the Universe needed a new form of energy: dark energy. Whereas matter clumps and clusters together under the influence of gravity, dark energy would penetrate all of space equally, from the densest galaxy clusters to the deepest, emptiest cosmic void. Whereas matter gets less dense as the Universe expands, since the same number of particles occupy a larger volume, the density of dark energy remains constant over time.

While matter and radiation become less dense as the Universe expands owing to its increasing volume, dark energy is a form of energy inherent to space itself. As new space gets created in the expanding Universe, the dark energy density remains constant. E. Siegel / Beyond The Galaxy

 

It's the total amount of energy in the Universe that governs what the expansion rate actually is. As time goes on and the matter density drops while the dark energy density doesn't, dark energy becomes more and more important relative to everything else. A distant galaxy, therefore, will not just appear to move away from us, but the more distant a galaxy is, the faster and faster it will appear to recede from us, with that speed increasing as time goes on.
That last part, where the speed increases as time goes on, only occurs if there's some form of dark energy in the Universe.

Standard candles (L) and standard rulers (R) are two different techniques astronomers use to measure the expansion of space at various times/distances in the past. Based on how quantities like luminosity or angular size change with distance, we can infer the expansion history of the Universe. NASA / JPL-Caltech

In the late 1990s, both the Supernova Cosmology Project and the High-z Supernova Search Team announced their results almost simultaneously, with both teams reaching the same conclusion: these distant supernovae are consistent with a Universe that's dominated by dark energy, and inconsistent with a Universe that has no dark energy at all.

Now, 20 years later, we have more than 700 of these supernovae, and they remain among the best evidence we have for dark energy's existence and properties. When a white dwarf — the corpse of a sun-like star — either accretes enough matter or merges with another white dwarf, it can trigger a Type Ia supernova, which is bright enough that we can observe these cosmic rarities from billions of light years away.

Two different ways to make a Type Ia supernova: the accretion scenario (L) and the merger scenario (R). But no matter how you analyze it, these indicators still show an accelerating Universe. NASA / CXC / M. Weiss

By the middle of the first decade of the 2000s, all of the reasonable alternative explanations for this observed phenomenon had been ruled out, and dark energy was an overwhelmingly accepted part of our Universe by the scientific community. Three of the leaders of those two teams — Saul Perlmutter, Brian Schmidt, and Adam Riess — were awarded the 2011 Nobel Prize in Physics for this result.

And yet, not everyone is convinced. Last week, Subir Sarkar of Oxford, along with a couple of collaborators, put forth a paper claiming that even today, with 740 Type Ia supernovae to work from, the supernova evidence only supports dark energy at the 3-sigma confidence level: far lower than what's required in physics. This is his second paper making this allegation, and the results have gotten quite a bit of news coverage.

This is a portion of a deep sky Hubble Space Telescope survey called GOODS North, which alludes to another possible selection effect: that most of the supernovae in the Universe are measured in a particular location on the sky. NASA, ESA, G. Illingworth (University of California, Santa Cruz), P. Oesch (University of California, Santa Cruz; Yale University), R. Bouwens and I. Labbé (Leiden University), and the Science Team

Unfortunately, Sarkar is not only wrong, he's wrong in a very specific way. Whenever you work in a field that isn't your own (he's a particle physicist, not an astrophysicist), you have to understand how that field works differently from your own, and why. If you neglect those assumptions, you get the wrong answer, and so you have to be careful about how you do your analysis.

In particle physics, there are always assumptions you make about event rates, backgrounds, and what you expect to see. In order to make a new discovery, you have to subtract out the anticipated signal from all other sources, and then compare what you see to what remains. It's how we've discovered every new particle for generations, including, most recently, the Higgs.

The discovery of the Higgs Boson in the di-photon (γγ) channel at CMS. Only by understanding the diphoton production in all the other Standard Model channels can we accurately detail the production of the Higgs.

If you don't make those assumptions, you won't be able to tease the legitimate signal out of the noise; there will be too much going on, and your significance will be too low. In astronomy and astrophysics, there are assumptions we make, too, in order to make our discoveries. Much like we assume the validity of the particles we've measured and their well-measured interactions to discover new ones, we make assumptions about the Universe.

We assume that General Relativity is correct as our theory of gravity. We assume that the Universe is filled with matter and energy that's roughly of the same density everywhere. We assume that Hubble's Law is valid. And we assume that these supernovae are good distance indicators for how the Universe expands. Sarkar makes these assumptions as well, and here's the graph he arrives at (from the 2016 paper) for the supernova data.

The figure representing the confidence in accelerated expansion and in the measurement of dark energy (y-axis) and matter (x-axis) from supernovae alone. Nielsen, Guffanti and Sarkar, (2016)

The y-axis indicates the percentage of Universe that's made of dark energy; the x-axis the percentage that's matter, normal and dark combined. The authors emphasize that while the best fit for the data does support the accepted model — a Universe that's roughly 2/3 dark energy and 1/3 matter — the red contours, representing 1σ, 2σ, and 3σ confidence levels, aren't overwhelmingly compelling. As Subir Sarkar says,

We analysed the latest catalogue of 740 Type Ia supernovae — over 10 times bigger than the original samples on which the discovery claim was based — and found that the evidence for accelerated expansion is, at most, what physicists call '3 sigma'. This is far short of the '5 sigma' standard required to claim a discovery of fundamental significance.

Sure, you get '3 sigma' if you make only those assumptions. But what about the assumptions he didn't make, that he really should have?

If you assume that, in addition to the raw supernova data, you live in a Universe that has at least some matter in it, you find that you must have a dark energy component in your Universe as well. Nielsen, Guffanti and Sarkar, (2016) / E. Siegel

You know, like the fact that the Universe contains matter. Yes, the value corresponding to the "0" value for matter density (on the x-axis) is ruled out because the Universe contains matter. In fact, we've measured how much matter the Universe has, and it's around 30%. Even in 1998, that value was known to a certain precision: it couldn't be less than about 14% or more than about 50%. So right away, we can place stronger constraints.

In addition, as soon as the first WMAP data came back, of the Cosmic Microwave Background, we recognized that the Universe was almost perfectly spatially flat. That means that the two numbers — the one on the y-axis and the one on the x-axis — have to add up to 1. This information from WMAP first came to our attention in 2003, even though other experiments like COBE, BOOMERanG and MAXIMA had hinted at it. If we add that extra flatness in, the "wiggle room" goes way, way down.

If you add in the data, completely independent of supernova data, that indicates that the Universe is flat, you find that the only way to have a Universe without acceleration is to have an unreasonably high matter density, something completely unrelated to supernova data. Nielsen, Guffanti and Sarkar, (2016) / E. Siegel

In fact, this crudely hand-drawn map I've made, overlaying the Sarkar analysis, matches almost exactly the modern joint analysis of the three major sources of data, which includes supernovae.

Constraints on dark energy from three independent sources: supernovae, the CMB and BAO. Note that even without supernovae, we’d need dark energy. More up-to-date versions of this graph are available, but the results are largely unchanged. Supernova Cosmology Project, Amanullah, et al., Ap.J. (2010)

What this analysis actually shows is just how incredible our data is: even with using none of our knowledge about the matter in the Universe or the flatness of space, we can still arrive at a better-than-3σ result supporting an accelerating Universe.

But it also underscores something else that's far more important. Even if all of the supernova data were thrown out and ignored, we have more than enough evidence at present to be extremely confident that the Universe is accelerating, and made of about 2/3 dark energy.

(Note that the new, 2018 paper makes a slightly different argument based on sky direction and distance to argue that the supernova evidence is only at 3-sigma significance. It is no more compelling than the 2016 argument that has been debunked here.)

The supernova data from the sample used in Nielsen, Guffati and Sarkar cannot distinguish at 5-sigma between an empty Universe (green) and the standard, accelerating Universe (purple), but other sources of information matter as well. Image credit: Ned Wright, based on the latest data from Betoule et al. (2014). Ned Wright's Cosmology Tutorial

We do not do science in a vacuum, completely ignoring all the other pieces of evidence that our scientific foundation builds upon. We use the information we have and know about the Universe to draw the best, most robust conclusions we have. It is not important that your data meet a certain arbitrary standard on its own, but rather that your data can demonstrate which conclusions are inescapable given our Universe as it actually is.

Our Universe contains matter, is at least close to spatially flat, and has supernovae that allow us to determine how it's expanding. When we put that picture together, a dark energy-dominated Universe is inescapable. Just remember to look at the whole picture, or you might miss out on how amazing it truly is.

Astrophysicist and author Ethan Siegel is the founder and primary writer of Starts With A Bang! His books, Treknology and Beyond The Galaxy, are available wherever books are sold.

Terraforming

From Wikipedia, the free encyclopedia

An artist's conception shows a terraformed Mars in four stages of development.

Terraforming or terraformation (literally, "Earth-shaping") of a planet, moon, or other body is the hypothetical process of deliberately modifying its atmosphere, temperature, surface topography or ecology to be similar to the environment of Earth to make it habitable by Earth-like life.

The concept of terraforming developed from both science fiction and actual science. The term was coined by Jack Williamson in a science-fiction short story ("Collision Orbit") published during 1942 in Astounding Science Fiction, but the concept may pre-date this work.

Even if the environment of a planet could be altered deliberately, the feasibility of creating an unconstrained planetary environment that mimics Earth on another planet has yet to be verified. Mars is usually considered to be the most likely candidate for terraforming. Much study has been done concerning the possibility of heating the planet and altering its atmosphere, and NASA has even hosted debates on the subject. Several potential methods of altering the climate of Mars may fall within humanity's technological capabilities, but at present the economic resources required to do so are far beyond that which any government or society is willing to allocate to it. The long timescales and practicality of terraforming are the subject of debate. Other unanswered questions relate to the ethics, logistics, economics, politics, and methodology of altering the environment of an extraterrestrial world.

History of scholarly study

The renowned astronomer Carl Sagan proposed the planetary engineering of Venus in an article published in the journal Science in 1961. Sagan imagined seeding the atmosphere of Venus with algae, which would convert water, nitrogen and carbon dioxide into organic compounds. As this process removed carbon dioxide from the atmosphere, the greenhouse effect would be reduced until surface temperatures dropped to "comfortable" levels. The resulting carbon, Sagan supposed, would be incinerated by the high surface temperatures of Venus, and thus be sequestered in the form of "graphite or some involatile form of carbon" on the planet's surface. However, later discoveries about the conditions on Venus made this particular approach impossible. One problem is that the clouds of Venus are composed of a highly concentrated sulfuric acid solution. Even if atmospheric algae could thrive in the hostile environment of Venus's upper atmosphere, an even more insurmountable problem is that its atmosphere is simply far too thick—the high atmospheric pressure would result in an "atmosphere of nearly pure molecular oxygen" and cause the planet's surface to be thickly covered in fine graphite powder. This volatile combination could not be sustained through time. Any carbon that was fixed in organic form would be liberated as carbon dioxide again through combustion, "short-circuiting" the terraforming process.

Sagan also visualized making Mars habitable for human life in "Planetary Engineering on Mars" (1973), an article published in the journal Icarus. Three years later, NASA addressed the issue of planetary engineering officially in a study, but used the term "planetary ecosynthesis" instead. The study concluded that it was possible for Mars to support life and be made into a habitable planet. The first conference session on terraforming, then referred to as "Planetary Modeling", was organized that same year.

In March 1979, NASA engineer and author James Oberg organized the First Terraforming Colloquium, a special session at the Lunar and Planetary Science Conference in Houston. Oberg popularized the terraforming concepts discussed at the colloquium to the general public in his book New Earths (1981). Not until 1982 was the word terraforming used in the title of a published journal article. Planetologist Christopher McKay wrote "Terraforming Mars", a paper for the Journal of the British Interplanetary Society. The paper discussed the prospects of a self-regulating Martian biosphere, and McKay's use of the word has since become the preferred term. In 1984, James Lovelock and Michael Allaby published The Greening of Mars. Lovelock's book was one of the first to describe a novel method of warming Mars, where chlorofluorocarbons (CFCs) are added to the atmosphere.

Motivated by Lovelock's book, biophysicist Robert Haynes worked behind the scenes to promote terraforming, and contributed the neologism Ecopoiesis, forming the word from the Greek οἶκος, oikos, "house", and ποίησις, poiesis, "production". Ecopoiesis refers to the origin of an ecosystem. In the context of space exploration, Haynes describes ecopoiesis as the "fabrication of a sustainable ecosystem on a currently lifeless, sterile planet". Fogg defines ecopoiesis as a type of planetary engineering and is one of the first stages of terraformation. This primary stage of ecosystem creation is usually restricted to the initial seeding of microbial life. As conditions approach that of Earth, plant life could be brought in, and this will accelerate the production of oxygen, theoretically making the planet eventually able to support animal life.

Aspects and definitions

Beginning in 1985, Martyn J. Fogg began publishing several articles on terraforming. He also served as editor for a full issue on terraforming for the Journal of the British Interplanetary Society in 1992. In his book Terraforming: Engineering Planetary Environments (1995), Fogg proposed the following definitions for different aspects related to terraforming:

• Planetary engineering: the application of technology for the purpose of influencing the global properties of a planet.
• Geoengineering: planetary engineering applied specifically to Earth. It includes only those macroengineering concepts that deal with the alteration of some global parameter, such as the greenhouse effect, atmospheric composition, insolation or impact flux.
• Terraforming: a process of planetary engineering, specifically directed at enhancing the capacity of an extraterrestrial planetary environment to support life as we know it. The ultimate achievement in terraforming would be to create an open planetary ecosystem emulating all the functions of the biosphere of Earth, one that would be fully habitable for human beings.

Fogg also devised definitions for candidate planets of varying degrees of human compatibility:

• Habitable Planet (HP): A world with an environment sufficiently similar to Earth as to allow comfortable and free human habitation.
• Biocompatible Planet (BP): A planet possessing the necessary physical parameters for life to flourish on its surface. If initially lifeless, then such a world could host a biosphere of considerable complexity without the need for terraforming.
• Easily Terraformable Planet (ETP): A planet that might be rendered biocompatible, or possibly habitable, and maintained so by modest planetary engineering techniques and with the limited resources of a starship or robot precursor mission.

Fogg suggests that Mars was a biologically compatible planet in its youth, but is not now in any of these three categories, because it can only be terraformed with greater difficulty.

Habitability requirements

An absolute requirement for life is an energy source, but the notion of planetary habitability implies that many other geophysical, geochemical, and astrophysical criteria must be met before the surface of an astronomical body is able to support life. Of particular interest is the set of factors that has sustained complex, multicellular animals in addition to simpler organisms on Earth. Research and theory in this regard is a component of planetary science and the emerging discipline of astrobiology. In its astrobiology roadmap, NASA has defined the principal habitability criteria as "extended regions of liquid water, conditions favorable for the assembly of complex organic molecules, and energy sources to sustain metabolism."

Preliminary stages

Once conditions become more suitable for life of the introduced species, the importation of microbial life could begin. As conditions approach that of Earth, plant life could also be brought in. This would accelerate the production of oxygen, which theoretically would make the planet eventually able to support animal life.

Prospective targets

Artist's conception of a terraformed Mars

Mars

In many respects, Mars is the most Earth-like planet in the Solar System. It is thought that Mars once had a more Earth-like environment early in its history, with a thicker atmosphere and abundant water that was lost over the course of hundreds of millions of years.

The exact mechanism of this loss is still unclear, though three mechanisms in particular seem likely: First, whenever surface water is present, carbon dioxide (CO
₂) reacts with rocks to form carbonates, thus drawing atmosphere off and binding it to the planetary surface. On Earth, this process is counteracted when plate tectonics works to cause volcanic eruptions that vent carbon dioxide back to the atmosphere. On Mars, the lack of such tectonic activity worked to prevent the recycling of gases locked up in sediments.

Second, the lack of a magnetosphere around Mars may have allowed the solar wind to gradually erode the atmosphere. Convection within the core of Mars, which is made mostly of iron, originally generated a magnetic field. However the dynamo ceased to function long ago, and the magnetic field of Mars has largely disappeared, probably due to "... loss of core heat, solidification of most of the core, and/or changes in the mantle convection regime." Results from the NASA MAVEN mission show that the atmosphere is removed primarily due to Coronal Mass Ejection events, where outbursts of high-velocity protons from the sun impact the atmosphere. Mars does still retain a limited magnetosphere that covers approximately 40% of its surface. Rather than uniformly covering and protecting the atmosphere from solar wind, however, the magnetic field takes the form of a collection of smaller, umbrella-shaped fields, mainly clustered together around the planet's southern hemisphere.

Finally, between approximately 4.1 and 3.8 billion years ago, asteroid impacts during the Late Heavy Bombardment caused significant changes to the surface environment of objects in the Solar System. The low gravity of Mars suggests that these impacts could have ejected much of the Martian atmosphere into deep space.

Terraforming Mars would entail two major interlaced changes: building the atmosphere and heating it. A thicker atmosphere of greenhouse gases such as carbon dioxide would trap incoming solar radiation. Because the raised temperature would add greenhouse gases to the atmosphere, the two processes would augment each other. Carbon dioxide alone would not suffice to sustain a temperature above the freezing point of water, so a mixture of specialized greenhouse molecules might be manufactured.

Artist's conception of a terraformed Venus

Venus

Terraforming Venus requires two major changes; removing most of the planet's dense 9 MPa carbon dioxide atmosphere and reducing the planet's 450 °C (723.15 K) surface temperature. These goals are closely interrelated, because Venus's extreme temperature is thought to be due to the greenhouse effect caused by its dense atmosphere. Sequestering the atmospheric carbon would likely solve the temperature problem as well.

Artist's conception of what the Moon might look like terraformed

The Moon

Although the gravity on Earth's moon is too low to hold an atmosphere for geological spans of time, if given an atmosphere, it would retain the atmosphere for spans of time that are long compared to human lifespans. Landis and others have thus proposed that it could be feasible to terraform the moon, although not all agree with that proposal. Landis estimates that a 1 PSI atmosphere of pure oxygen on the moon would require on the order of two hundred trillion tons of oxygen, and suggests it could be produced by reducing the oxygen from an amount of lunar rock equivalent to a cube about fifty kilometers on an edge. Alternatively, he suggests that the water content of "fifty to a hundred comets" the size of Halley's comet would do the job, "assuming that the water doesn't splash away when the comets hit the moon." Likewise, Benford calculates that terraforming the moon would require "about 100 comets the size of Halley's."

Other bodies in the Solar System

Other possible candidates for terraforming (possibly only partial or paraterraforming) include Titan, Callisto, Ganymede, Europa, and even Mercury, Saturn's moon Enceladus, and the dwarf planet Ceres.

Other possibilities

Biological Terraforming

Many proposals for planetary engineering involve the use of genetically engineered bacteria.

As synthetic biology matures over the coming decades it may become possible to build designer organisms from scratch that directly manufacture desired products efficiently. Lisa Nip, Ph.D. candidate at the MIT Media Lab's Molecular Machines group, said that by synthetic biology, scientists could genetically engineer humans, plants and bacteria to create Earth-like conditions on another planet.

Gary King, microbiologist at Louisiana State University studying the most extreme organisms on Earth, notes that "synthetic biology has given us a remarkable toolkit that can be used to manufacture new kinds of organisms specially suited for the systems we want to plan for" and outlines the prospects for terraforming, saying "we'll want to investigate our chosen microbes, find the genes that code for the survival and terraforming properties that we want (like radiation and drought resistance), and then use that knowledge to genetically engineer specifically Martian-designed microbes". He sees the project's biggest bottleneck in the ability to genetically tweak and tailor the right microbes, estimating that this hurdle could take "a decade or more" to be solved. He also notes that the it would be best to develop "not a single kind microbe but a suite of several that work together".

DARPA is researching using photosynthesizing plants, bacteria, and algae grown directly on the Mars surface that could warm up and thicken its atmosphere. In 2015 the agency and some of its research partners have created a software called DTA GView − a 'Google Maps of genomes', in which genomes of several organisms can be pulled up on the program to immediately show a list of known genes and where they are located in the genome. According to Alicia Jackson, deputy director of DARPA's Biological Technologies Office by this they have developed a "technological toolkit to transform not just hostile places here on Earth, but to go into space not just to visit, but to stay".

Paraterraforming

Also known as the "worldhouse" concept, paraterraforming involves the construction of a habitable enclosure on a planet which encompasses most of the planet's usable area. The enclosure would consist of a transparent roof held one or more kilometers above the surface, pressurized with a breathable atmosphere, and anchored with tension towers and cables at regular intervals. The worldhouse concept is similar to the concept of a domed habitat, but one which covers all (or most) of the planet.

Adapting humans

It has also been suggested that instead of or in addition to terraforming a hostile environment humans might adapt to these places by the use of genetic engineering, biotechnology and cybernetic enhancements.

Issues

Ethical issues

There is a philosophical debate within biology and ecology as to whether terraforming other worlds is an ethical endeavor. From the point of view of a cosmocentric ethic, this involves balancing the need for the preservation of human life against the intrinsic value of existing planetary ecologies.

On the pro-terraforming side of the argument, there are those like Robert Zubrin, Martyn J. Fogg, Richard L. S. Taylor and the late Carl Sagan who believe that it is humanity's moral obligation to make other worlds suitable for life, as a continuation of the history of life transforming the environments around it on Earth. They also point out that Earth would eventually be destroyed if nature takes its course, so that humanity faces a very long-term choice between terraforming other worlds or allowing all terrestrial life to become extinct. Terraforming totally barren planets, it is asserted, is not morally wrong as it does not affect any other life.

The opposing argument posits that terraforming would be an unethical interference in nature, and that given humanity's past treatment of Earth, other planets may be better off without human interference. Still others strike a middle ground, such as Christopher McKay, who argues that terraforming is ethically sound only once we have completely assured that an alien planet does not harbor life of its own; but that if it does, we should not try to reshape it to our own use, but we should engineer its environment to artificially nurture the alien life and help it thrive and co-evolve, or even co-exist with humans. Even this would be seen as a type of terraforming to the strictest of ecocentrists, who would say that all life has the right, in its home biosphere, to evolve without outside interference.

Economic issues

The initial cost of such projects as planetary terraforming would be gargantuan, and the infrastructure of such an enterprise would have to be built from scratch. Such technology is not yet developed, let alone financially feasible at the moment. John Hickman has pointed out that almost none of the current schemes for terraforming incorporate economic strategies, and most of their models and expectations seem highly optimistic.

Political issues

National pride, rivalries between nations, and the politics of public relations have in the past been the primary motivations for shaping space projects. It is reasonable to assume that these factors would also be present in planetary terraforming efforts.

In popular culture

Terraforming is a common concept in science fiction, ranging from television, movies and novels to video games.