Life as the Only Reason for the Existence of N2–O2-Dominated Atmospheres

The Earth’s N2-dominated atmosphere is a very special feature. Firstly, N2 as main gas unique on terrestrial planets in the inner Solar System and gives hint for tectonic activity. Studying origins of atmospheric nitrogen its stability provides insights into uniqueness habitat. Secondly, coexistence O2 within an unequaled entire System. Such combination strongly linked to existence aerobic lifeforms. availability surface, ocean, can enable or prevent habitability planet, since vitally required by all known In present work, different nitrogen, dominated atmospheres, development early are discussed. We show why N2–O2 atmospheres constitute biomarker not only any lifeforms but a-erobic lifeforms, which were first major step that led highly developed life Earth.