(* this breaks *) Table[{s,p}, {s,AstronomicalData[p,”Satellites”]}, {p,AstronomicalData[“Planet”]} ]; Table::iterb: Iterator {s, $ Failed} does not have appropriate bounds. (* but if you switch the iteration order, it works fine *) Table[{s,p}, {p,AstronomicalData[“Planet”]}, {s,AstronomicalData[p,”Satellites”]} ]; Why? (I don’t think this is specific to AstronomicalData, that’s just where I ran across it)Read more