PARLA laser at the VLT

The PARLA laser is used to generate an artificial star about 90 kilometres up in the atmosphere. By creating and observing such a bright point of light astronomers can probe the turbulence in the layers of the atmosphere above the telescope. This information is then used to adjust deformable mirrors in real time in order to correct most of the disturbances caused by the constant movement of atmosphere and create much sharper images. Read more on the ESO announcement ann13010.