In this current context of scientific explosionat all levels (although the exponential growth is not thesame in all scientific disciplines), we find the advent ofnew disciplines and subdisciplines that help us toclassify the areas of knowledge.Thus, to order this informative explosion, itwas convenient to establish a classification system forthe different areas of study. The UNESCO InternationalNomenclature for the fields of Science and Technologywas proposed in 1973 and 1974 by the Science andTechnology Policy Divisions of Science andTechnology of UNESCO and adopted by the Scientificand Technical Research Advisory Commission. It is aknowledge classification system widely used in themanagement of research projects and doctoral theses.And, as a sign that science always brings newhorizons to knowledge, new actors are alwaysappearing in this classification system.In the field that occupies us, however, we findourselves with a great absence. The "Astrobiology",does not appear in the listings of UNESCO. But yes, wefind in them the term "Exobiology" [2, 3]. This "partial"absence denotes the novelty that is still today toscientifically consider the study of life outside Earth.Indeed, until very recently and by manyscientists, it was considered "Exobiology" or"Astrobiology" (which we will consider synonyms), ascience without an area of study. This was especiallytrue until 1995, when Michel Mayor and Didier Quelozdiscovered the first extrasolar planet, 51 Pegasi b.Fortunately, today things are beginning to change andmore and more scientists believe that life will be aubiquitous phenomenon, which will occur anywhere inthe universe where the conditions are right for it.Life will then be an epiphenomenon, an eventthat has no choice but to occur, as soon as thecomplexity of the chemical organization of matterreaches the critical point of interaction between thetrace elements, the essential elements for life. At thebase of it we will find carbon, hydrogen, oxygen,nitrogen, phosphorus and sulphur.As life will be a ubiquitous phenomenon,finally today we already intuit that not even a planet isnecessary for life to prosper, and that life could bemaintained in interstellar space, without planetarysubstratum. But before continuing, it is convenient tofix some definitions.The debate on what is life? has occupied allgenerations of thinkers. It is a very difficult concept todefine. Currently there is consensus in affirming thatlife is a self-contained, autopoietic chemical system(self-sufficient exchanging energy with theenvironment in which it is located), capable ofreproducing itself and experiencing evolution [4]. It isa broad definition. In it the minerals could fit, and eventhe stars themselves, as we will see later.So, in view of the complexity of theknowledge that we are slowly acquiring about theuniverse, and given the challenges posed by thepossibility of assuming that life will be found virtuallyanywhere, it is convenient to establish a series of ethicalvalues that allow a positive integration in the culturalbaggage of society of the new limits of knowledge thatscience gives us.For this reason, a "Philosophy of Science" -code UNESCO 7205.01- was established, under whichsince the 80s we can find the "Philosophy of Biology".Before delving into the Philosophy ofAstrobiology, we will give its definition, based on theconcepts of "Philosophy" and "Astrobiology".
Authors argue that the growth of the sciences in human culture has driven the need to expand the ontology of scientific categories. As astrobiology matures, more complex studies across disciplines are needed to address evolving areas - e.g., exobiology, philosophy of astrobiology, or my own term exoastronomy which I coined in 2018. These are missing from the UNESCO International nomenclature as of 2025/2026.