Yepun on the VLT platform

This image features the fourth Unit Telescope of ESO's Very Large Telescope (VLT), alongside one of its smaller companions. 

The fourth Unit Telescope, also known as Yepun, is seen here firing its laser guide star into the night sky. This guide star is used by astronomers as part of the VLT's advanced optics system, which corrects for atmospheric disturbance and allows for much more detailed study of the skies. 

The smaller telescope on the right is the second of four 1.8-m Auxiliary Telescopes that can be found on the VLT platform.