Atmosphere/summary

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Atmosphere

Atmosphere Classifications -> Summary Synopsis Paragraphs[edit]

Atmosphere Codes (AC) Classifications -> Summary Synopsis Paragraphs
Atmo Code Statement (Summary Synopsis Paragraph) Remarks
Vacuum Atmosphere (Atmo Type: 0) World has a pressure of less than 0.001 atmospheres, which requires the use of a vacc suit. Example: Terran Moon
Trace Atmosphere (Atmo Type: 1) World has a pressure of less than 0.1 atmospheres, which requires the use of a vacc suit. Example: Mercury (world)
Very Thin Atmosphere & Tainted Atmosphere (Atmo Type: 2) World has a pressure of 0.10 to 0.42 atmospheres. Example: Very high altitude Terra
  • At altitudes above 4,000 meters on Terra, such as most of the Tibetan plateau, the oxygen content in every breath full drops almost to 50%, whilst above 7,000 meters (the peaks of the Himalaya mountains) the lack of available oxygen reaches lethal levels. This extreme altitude on the 'roof of the world' is equivalent to the IISS Scout Code atmosphere of Very Thin. For most explorers, respirators or oxygen masks will be required in this type of environment. [1]
Very Thin Atmosphere (Atmo Type: 3) World has a pressure of 0.10 to 0.42 atmospheres. Example: Very high altitude Terra
  • At altitudes above 4,000 meters on Terra, such as most of the Tibetan plateau, the oxygen content in every breath full drops almost to 50%, whilst above 7,000 meters (the peaks of the Himalaya mountains) the lack of available oxygen reaches lethal levels. This extreme altitude on the 'roof of the world' is equivalent to the IISS Scout Code atmosphere of Very Thin. For most explorers, respirators or oxygen masks will be required in this type of environment. [2]
Thin Atmosphere & Tainted Atmosphere (Atmo Type: 4) World has a pressure of 0.43 to 0.70 atmospheres. Example: High altitude Terra
  • At altitudes above 2,500 meters on Terra, the air pressure drops to around 0.70 that of sea level. This is equivalent to the IISS Scout Code atmosphere type of Thin. Sophonts who are not adapted to such conditions can suffer from altitude sickness, with headaches, nausea, extreme tiredness, breathlessness and body pain. Associated high blood pressure can cause complications for pregnant women. [3]
Thin Atmosphere (Atmo Type: 5) World has a pressure of 0.43 to 0.70 atmospheres. Example: High altitude Terra
  • At altitudes above 2,500 meters on Terra, the air pressure drops to around 0.70 that of sea level. This is equivalent to the IISS Scout Code atmosphere type of Thin. Sophonts who are not adapted to such conditions can suffer from altitude sickness, with headaches, nausea, extreme tiredness, breathlessness and body pain. Associated high blood pressure can cause complications for pregnant women. [4]
Standard Atmosphere (Atmo Type: 6) World has a pressure of 0.71 to 1.49 atmospheres. Example: Standard altitude Terra
  • On Earth, sophonts have little experience of differing atmospheric pressures, and so many underestimate how much of an impact this factor may have on everyday life. Terran inhabitants are actually living near the bottom of an ocean of air. At sea level, the weight of the air presses down on its inhabitants with a pressure of 1.0 kg per squared centimeter. At higher altitudes, less air means less weight and less pressure. The pressure and density of air decreases with increasing elevation.
Standard Atmosphere & Tainted Atmosphere (Atmo Type: 7) World has a pressure of 0.71 to 1.49 atmospheres. Example: Standard altitude Terra
  • On Earth, sophonts have little experience of differing atmospheric pressures, and so many underestimate how much of an impact this factor may have on everyday life. Terran inhabitants are actually living near the bottom of an ocean of air. At sea level, the weight of the air presses down on its inhabitants with a pressure of 1.0 kg per squared centimeter. At higher altitudes, less air means less weight and less pressure. The pressure and density of air decreases with increasing elevation.
Dense Atmosphere (Atmo Type: 8) World has a pressure of 1.50 to 2.49 atmospheres. Example: Dense, High (D): These worlds have thick N2/O2 atmospheres, but their mean surface pressure is too high to support unprotected human life (high pressure nitrogen and oxygen are deadly to humans). However, pressure naturally decreases with increasing altitude, so if there are highlands at the right altitude the pressure may drop enough to support human life. Alternatively, there may not be any topography high enough for humans to inhabit, necessitating floating gravitic or dirigible habitats or sealed habitats on the surface. [5]
Dense Atmosphere & Tainted Atmosphere (Atmo Type: 9) World has a pressure of 1.50 to 2.49 atmospheres. Example: Dense, High (D): These worlds have thick N2/O2 atmospheres, but their mean surface pressure is too high to support unprotected human life (high pressure nitrogen and oxygen are deadly to humans). However, pressure naturally decreases with increasing altitude, so if there are highlands at the right altitude the pressure may drop enough to support human life. Alternatively, there may not be any topography high enough for humans to inhabit, necessitating floating gravitic or dirigible habitats or sealed habitats on the surface. [6]
Conventional Exotic Atmosphere (Atmo Type: A or 10) World has a pressure of variable atmospheres. Example: Exotic or Unusual Atmospheres are most noted for widely diverging from the mostly acceptable spectrum of atmospheric temperature, pressure, and gas compositions from the more conventional codes for atmospheres well suited to the major races and conventional life. They typically have atmospheres very divergent from the roughly 80% Nitrogen and 20% Oxygen mixtures of Terran-like life-supporting worlds.
Corrosive Atmosphere & Conventional Exotic Atmosphere (Atmo Type: B or 11) World has a pressure of variable atmospheres. Example: Corrosive (B): Corrosive atmospheres are highly dangerous. A sophont who breathes in a corrosive atmosphere will suffer damage every few minutes until death occurs. [7]
Insidious Atmosphere & Conventional Exotic Atmosphere (Atmo Type: C or 12) World has a pressure of variable atmospheres. Example: Insidious (C): An insidious atmosphere is like a corrosive one, but it is so corrosive that it attacks equipment as well. The chief danger in an insidious atmosphere is that the toxic gases will destroy the seals and filters on a traveller’s protective gear. An insidious atmosphere worms its way past protection after just a few hours on average, although vigilant maintenance or advanced protective gear can prolong survival times. [8]
Dense Atmosphere & High Pressure Atmosphere & Unusual Exotic Atmosphere (Atmo Type: D or 13) World has a pressure of 2.5 or greater atmospheres.
  • A Dense & High Pressure Atmosphere typically requires no survival gear under many conditions.
  • Pressure at or below sea level is too great to support life but is breathable at higher altitudes.
  • TL-5 or more advanced survival gear is required to settle this world.
Example: High Pressure Atmospheres are classified as possessing 2.5 standard atmospheres or more of pressure.
Ellipsoid Atmosphere & Unusual Exotic Atmosphere (Atmo Type: E or 14) World has a pressure of 0.5 or less atmospheres.
  • An Ellipsoid Atmosphere typically requires no survival gear under many conditions.
  • The world’s surface is ellipsoidal, not spherical. Because the atmosphere remains spherical, surface atmospheric pressure ranges from very high at the middle to very low at the ends.
  • Breathable bands may exist at some point within the range of pressure.
  • TL-5 or more advanced survival gear is required to settle this world.
Example: Ellipsoid Atmospheres are known for having extremely uneven applications of atmosphere, air pressure, and environmental characteristics. This can lead to extremely variable environments and species that can dwell in one environment, but not in a neighboring one only a short distance away. The differences between niche species strongly tend to be more pronounced on an ellipsoidal world.
Thin Atmosphere & Low Pressure Atmosphere & Unusual Exotic Atmosphere (Atmo Type: F or 15) World has a pressure of variable atmospheres.
  • A Thin & Low Pressure & Unusual Exotic Atmosphere typically requires no survival gear under many conditions.
  • This world is large and massive, with a thin atmosphere which settles to the lowest levels of the terrain.
  • The atmosphere is un-breathable at most altitudes except the very low ones (…as in depressions or deep valleys).
  • TL-8 or more advanced survival gear is required to settle this world.
Example: One of the advantages of living on a low pressure or vacuum world is easier access to space. Planetary spaceports on low pressure worlds can often provide construction shipyards at a drastically reduced cost, often competitive with orbital shipyards.
  1. Paul Elliott. The Universal World Profile (Zozer Games, 2016), 14.
  2. Paul Elliott. The Universal World Profile (Zozer Games, 2016), 14.
  3. Paul Elliott. The Universal World Profile (Zozer Games, 2016), 14.
  4. Paul Elliott. The Universal World Profile (Zozer Games, 2016), 14.
  5. Gareth Hanrahan. Mongoose Traveller Main Rulebook (Mongoose Publishing, 2008), 170.
  6. Gareth Hanrahan. Mongoose Traveller Main Rulebook (Mongoose Publishing, 2008), 170.
  7. Gareth Hanrahan. Mongoose Traveller Main Rulebook (Mongoose Publishing, 2008), 170.
  8. Gareth Hanrahan. Mongoose Traveller Main Rulebook (Mongoose Publishing, 2008), 170.