#109 | ast03 – Comparative between Mars and Earth

Hi everyone,

I’m trying to organize my time for the last month of my “scholarship”, I need to do some stuff in parallel too… So, like I said previously, I am going to take a rest and trying to process my thoughts since I memorized a lot of things this week. Bach is also quite busy with his hacker/pentester job. Anyway, we are trying our best to keep the pace of the articles.
Today, I’ll take a little leap on astronomy since I am not at home and I can’t really enjoy my telescope. I will compare Earth to Mars and tell you the difference and the criteria you need to know to build on Mars (and there are a lot of them, so I can’t iterate everything in details). I will talk about it because the architecture needs to adapt to all these criteria even if it is a concept art… And since I am still trying to improve the concept, I’ve taken a look back to these criteria recently.

There is a little tablature made by Tristan Bassinghwaighte (one of the member crew on the Hi-Seas IV mission) on his dissertation. You can see some divergence between the different “worlds” but Mars is the one we will interest in.

fig.01 – Mars has the 1/3 of gravity compared to the Earth, that means that you need less effort to go up the stairs, but it also means you will lose some muscular weight. It is important to keep the body healthy and the bones density correct. If you translate in architecture, it means you need to make more steps for your stair and more height.

The atmosphere in Mars is different from Earth because it is rich in carbon dioxygen. However, it also means that you can grow plants if you compressed the air and filter it. Radiation is a more messy stuff since it can affect human DNA. The cells can’t survive with a direct exposure from the sun radiation and cosmic rays: it means you need to make thick layers of walls with regolith or with ice, or other good isolation materials to protect the crewmembers from these treats. By isolation, it also means that you need to prevent the extreme temperature.
These criteria come with waste & water management (filtering the waste to make clean water or to make fertilizer), food stock (making your own food by culture, irrigation, etc), sustainable energy (solar panel, improving the electricity system), communication (how to be able to communicate with the team and to interact from Mars to Earth if you know there is a 20 min delay), psychological (how can you survive in isolation and confined spaces), social and economic matters (you need to think about soundproof materials and make intimacy spaces for individuals. The hab needs to be built with cheap materials). Of course, there is still a lot of criteria that you need to take into account. However, these ones are the most important.

I’ve also observed some mistakes in my previous thoughts. The inclination of Mars revolution is approximatively the same as the Earth (about ~25,19° of axial tilt for ~23,23° on Earth) and the day is also near to a “day” (24h37 min for Mars and 24h for Earth) however, the diameter of the two planets are different. Earth is about twice larger than Mars and Mars take twice is time to get around the sun, it means about two years compared to the Earth. So, you can’t really use the same sunpath diagram for Earth on Mars. In fact, you need to change the sunpath diagram a little bit if you want to use it.
So, more than a real tool to make my project, the sunpath diagram is a analog tool to give a concept of how a sunpath diagram is working and could be useful for the next projects on Mars or on other extraplanetary planets.

What did I learn?

  • The exact name of the inclination (“axial tilt”) and the real number on Mars.
  • Sunpath diagram modifier


Bassingthwaighte, Tristan S.., The Design of Habitats for the Long-Term Health of Inhabitants in the Extreme Environments of Earth and Outer Space, University of Hawai’i at Manoa, ProQuest Dissertations Publishing, 2017. 10656561.

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