The open star cluster Messier 21 as imaged by the Vera C. Rubin Observatory
Located near the Trifid Nebula, Messier 21 is relatively young and tightly packed with small, dim stars.
Credit: RubinObs/NOIRLab/SLAC/NSF/DOE/AURA
https://noirlab.edu/public/images/noirlab2521ag