Katie MackHave you heard about JWST seeing galaxies that shouldn’t exist? There’s more to that story!
My latest for BBC Science Focus: https://www.sciencefocus.com/comment/james-webb-space-telescope-ancient-galaxies
aeva@AstroKatie this stuff is so neat. how do we tell if something is red shifted vs just being red to begin with?
@aeva Good question! Main way is to use patterns of known absorption or emission lines. They’ll get shifted to longer wavelengths but will appear at the same places relative to each other in the spectrum
Roc 
@AstroKatie @aeva Her explanation is pretty good I think https://youtu.be/2VVVADtXNBE?t=1427 (time at 23:47)