Editing Planetary engineering (section)

=== Developing microorganisms for seeding ===
Natural or engineered microorganisms must be created or discovered that can withstand the harsh environments of Mars. The first organisms used must be able to survive exposure to ionizing radiation and the high concentration of {{CO2}} present in the Martian atmosphere.<ref name="Todd" /> Later organisms such as multicellular plants must be able to withstand the freezing temperatures, withstand high {{CO2}} levels, and produce significant amounts of {{chem2|O2}}.

Microorganisms provide significant advantages over non-biological mechanisms. They are self-replicating, negating the needs to either transport or manufacture large machinery to the surface of Mars. They can also perform complicated chemical reactions with little maintenance to realize planet-scale terraforming.<ref>{{cite journal |last1=Conde-Pueyo |first1=Nuria |last2=Vidiella |first2=Blai |last3=Sardanyés |first3=Josep |last4=Berdugo |first4=Miguel |last5=Maestre |first5=Fernando T. |last6=de Lorenzo |first6=Victor |last7=Solé |first7=Ricard |title=Synthetic Biology for Terraformation Lessons from Mars, Earth, and the Microbiome |journal=Life |date=9 February 2020 |volume=10 |issue=2 |page=14 |doi=10.3390/life10020014 |pmid=32050455 |pmc=7175242 |doi-access=free |bibcode=2020Life...10...14C }}</ref>