>But even so, the scientists were surprised to find barium, which is 2.5 times heavier than iron, in the upper atmospheres of WASP-76 b and WASP-121 b.

It's amazing how often it seems that scientists are "surprised" - i.e. their theories were not borne out by the observational evidence. Perhaps because it's surprising, that makes it more headline-worthy, therefore there would be a bias in what gets reported. It would be interesting to see a meta-analysis of the "surprise" factor for study results.