Having observed that the notion of trace is used in disciplines whose subjects and methods often stand far apart, the author has put forward some definitions from French anthroposemiotic research (signe-trace, signe-signal, "echoing of traces" etc.). The propositions result from her own findings in professional situations of communication. In this article, B. Galinon-Mélénec explains that confusing the sign and the trace is an anthropocentric view and that "if any sign is, in fact, a "signe-trace", a trace is not necessarily a sign". The latest scientific discoveries have led the author to propose a new anthropological definition spanning time: the Homme-Trace. Revealed by both anthropology and astrophysics, traces of the distant past make it possible to question the trace in terms of processes, interactions (human or nonhuman), systems and complexity. This paper serves as a basis for debate within the international and interdisciplinary e.laboratory "Human-Trace-Complex-Systems", with the aim of developing a collective intelligence of the notion of Trace. All disciplines are invited to respond to this substantial societal challenge.