By focusing on a specific episode of 20th Century physics — the discovery of parity violation in 1957 — the paper presents a study of the types of explanations of the crucial experiment as they are found in different editorial categories: a peer-review journal, a popular science book, an encyclopedia and a newspaper articles. The study provides a fine-grained description of the mechanism of the explanation as elaborated in non-specialist accounts of the experiment and identifies original, key-explanatory elements which characterize them. In so doing, the paper presents a reflection on the processes of transformation and adaptation implied by the circulation of knowledge — which features as a productive process in its own right — and shows which further insights a focus on explanation can offer to the current historical researches on science communication.