This Laser Is Not Zapping Space Invaders

No, the astronomers at the European Southern Observatory are not playing a galactic-scale Space Invaders. They are just exciting atoms in the upper atmosphere, creating an artificial star 90km above Earth.

Astronomers at the Paranal Observatory make crystal clear pictures using this method, which is called Laser Guide Star. The LGS is used as a reference for the adaptive optics system of the Very Large Telescope array, the four deformable mirror-based telescopes at the top of Cerro Paranal, Chile.

Monitoring the artificial star, the electronic systems of the VLT can compensate for atmospheric distortion deforming the telescopes mirrors in real time. The result are crystal clear pictures that rival those of the Hubble.

In this picture - taken in August by ESO Photo Ambassador Yuri Beletsky with a wide-angle lens - scientists are pointing the laser at the Milky Way's galactic core. [European Southern Observatory via Discover Magazine]