The VLT’s night light, P. Horálek/ESO [CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/)]

www.eso.org/public/images/potw1736a/

Yepun (UT4), one of the four 8.2-metre Unit Telescopes comprising ESO’s Very Large Telescope (VLT), shoots a laser beam up into the dark night sky over ESO’s Paranal Observatory in Chile