Carl Sagan began using the term settlement in 1977 to avoid colonialist connotations. The US State Department issued clear guidance against using the word colonization decades ago.
Atmospheric pressure sits at 0.06 percent of Earth's sea level pressure, creating conditions below the Armstrong limit where humans cannot survive without pressure suits. Oxygen makes up only 0.16 percent of the Martian atmosphere while carbon dioxide dominates at 95 percent concentration.
Jean-Marc Salotti calculated minimum colony size requirements through mathematical modeling and suggests 110 people form the smallest viable population to prevent genetic problems. Other studies propose populations ranging from 198 up to 10,000 individuals depending on specific needs.
Scientists estimate travel time using Hohmann transfer orbits takes approximately nine months. Advanced propulsion systems like Variable Specific Impulse Magnetoplasma Rocket might cut transit times to forty days while nuclear rockets could potentially achieve trips lasting about two weeks.
The 1967 United Nations Outer Space Treaty prohibits countries from claiming ownership of space territories. Many articles prevent legal colonization of outer space regions.