(2015 Photo Contest Winner) "This picture was taken at the Andes Lidar Observatory, located in Cerro Pachón, Chile (30S, 71W). The yellow Na laser is used to probe the upper mesosphere and lower thermosphere. I took the picture, while the “ALO” writing on the wall of the observatory was made by John Smith at U of Colorado at Boulder. The picture was taken on May 29, 2014." - Alan Liu