Carbon dioxide levels in planet's atmosphere could be used to measure its habitability
New research suggests that the presence of liquid water on a planet can be indicated by lower carbon dioxide levels compared to neighboring planets. This drop in carbon dioxide levels may be due to the absorption of the gas by an ocean or isolation by biomass on a planetary scale. Scientists have devised a new 'habitability signature' that can detect habitability and potential for hosting liquid water. This signature can also serve as a biosignature, as living organisms capture carbon dioxide and emit oxygen.