User:Mcurr/sandbox
From Wikipedia, the free encyclopedia
For other uses, see Biomarker (disambiguation).
A biosignature (sometimes called chemical fossil or molecular fossil) is any substance ā such as an element, isotope, or molecule ā or phenomenon that provides scientific evidence of past or present life.[1][2][3] Measurable attributes of life include its complex physical and chemical structures and also its use of free energy and the production of biomass and wastes. In essence, a biosignature is evidence for living organisms outside the Earth and can be directly or indirectly detectable through searching for their unique byproducts.