It has been argued that introducing AI to creative practices destroys spontaneity, intuition and serendipity. However, the design of systems that leverage complex interactions between citizen scientists (members of the public engaged in research tasks) and computational AI methods have the potential to facilitate creative exploration and chance encounters. Drawing from theories and literature about serendipity and computation, this article points to three interrelated aspects that support the emergence of serendipity in hybrid citizen science systems: the task environment; the characteristics of citizen scientists; and anomalies and errors.