![ESO on Twitter: "@IDLofficial 7/ ESO's #VLT has a cutting-edge Laser Guide Star Facility (4LGSF), that produce four artificial stars by exciting sodium atoms at an altitude of 90 km. Read more ESO on Twitter: "@IDLofficial 7/ ESO's #VLT has a cutting-edge Laser Guide Star Facility (4LGSF), that produce four artificial stars by exciting sodium atoms at an altitude of 90 km. Read more](https://pbs.twimg.com/media/FwPPW3CX0AE5Oth.jpg:large)
ESO on Twitter: "@IDLofficial 7/ ESO's #VLT has a cutting-edge Laser Guide Star Facility (4LGSF), that produce four artificial stars by exciting sodium atoms at an altitude of 90 km. Read more
![ESO on Twitter: "The #Paranal Observatory affords the most spectacular views of the cosmos! https://t.co/tNVVaeANN1 https://t.co/2LrD2kGVbL" / Twitter ESO on Twitter: "The #Paranal Observatory affords the most spectacular views of the cosmos! https://t.co/tNVVaeANN1 https://t.co/2LrD2kGVbL" / Twitter](https://pbs.twimg.com/media/CXzrGMuWcAE_dJK.jpg:large)
ESO on Twitter: "The #Paranal Observatory affords the most spectacular views of the cosmos! https://t.co/tNVVaeANN1 https://t.co/2LrD2kGVbL" / Twitter
![English: Aerial view of the ESO Very Large Telescope (VLT), atop Cerro Paranal, in the Chilean Atacama Desert. On the low-left side of the platform, the buildings of the four giant 8.2-metre English: Aerial view of the ESO Very Large Telescope (VLT), atop Cerro Paranal, in the Chilean Atacama Desert. On the low-left side of the platform, the buildings of the four giant 8.2-metre](https://c8.alamy.com/comp/2BAMBHN/english-aerial-view-of-the-eso-very-large-telescope-vlt-atop-cerro-paranal-in-the-chilean-atacama-desert-on-the-low-left-side-of-the-platform-the-buildings-of-the-four-giant-82-metre-unit-telescopes-uts-are-clearly-distinguishable-the-uts-can-observe-either-individually-or-combined-by-two-or-three-using-a-technique-called-interferometry-their-position-in-the-platform-is-the-one-which-allows-the-maximum-number-of-possible-configurations-aligned-on-the-right-of-the-uts-are-the-four-18-metre-auxiliary-telescopes-ats-entirely-dedicated-to-interferometric-observations-the-ats-ca-2BAMBHN.jpg)
English: Aerial view of the ESO Very Large Telescope (VLT), atop Cerro Paranal, in the Chilean Atacama Desert. On the low-left side of the platform, the buildings of the four giant 8.2-metre
![From ESO: “Active Optics – Inventing a game changer” Nothing Really New, but Important Thanks to ESO | sciencesprings From ESO: “Active Optics – Inventing a game changer” Nothing Really New, but Important Thanks to ESO | sciencesprings](https://i0.wp.com/cdn.eso.org/images/screen/eso9940b.jpg)