The European Southern Observatory which has its Very Large Telescope array in Chile, were able to create the first artificial star in the Southern Hemisphere, allowing astronomers to study the Universe in the finest detail. From the Press release “This artificial laser guide star makes it possible to apply adaptive optics systems, that counteract the blurring effect of the atmosphere, almost anywhere in the sky.”.

And how does this work? From the release:

“The laser beam, shining at a well-defined wavelength, makes the layer of sodium atoms that is present in Earth’s atmosphere at an altitude of 90 kilometres glow. The laser is hosted in a dedicated laboratory under the platform of Yepun (which is a Unit Telescope of the Very Large Telescope). A custom-made fibre carries the high power laser to the launch telescope situated on top of the large Unit Telescope.”

ESO Press Release