Astronomers Celebrate “Celestial Pollution” From Perseid Meteor Shower

Close up of the Gemini South (GeMS) laser which splits into 5 points to create a 'constellation' of guide stars for improved corrections over a larger patch of sky. The points at the end of the laser "columns" are where the laser light excites sodium atoms about 90 kilometers overhead and produces laser guide stars used for adaptive optics. The visibility of the laser "columns" beneath the laser guide star "constellation" is due to scattering of the laser's light by dust and moisture in the lower atmosphere.