Copyright © Cambridge University Press 2018. Astrobioethics is an emerging discipline that studies, evaluates and analyses the moral, legal and social issues of the search for life in the Universe. As a new field of study, it requires an epistemological foundation to be able to be recognized as an academic discipline. In order to achieve this, it is important to understand the disciplinary nature of astrobiology as a transdisciplinary form of research, above the multi and interdisciplinary levels, although this does not necessarily mean discarding them. In addition, the questions and topics of each subdivision of astrobioethics studies are specified and explained in this paper.