VLT´s Auxiliary Telescopes opening

The sun has set at ESO´s Paranal Observatory and the Very Large Telescope (VLT) is preparing for a night of observations. The Auxiliary Telescopes 3 (AT3) and 4 (AT4, on the right) are opening. While the four 8.2-metre Unit Telescopes (UTs) are typically already opened at this time of the day, the four 1.8-metre Auxiliary Telescopes (ATs) need to wait that the sun is below the horizon to avoid the possibility that sunlight could shine directly on one of the mirrors. In this picture, taken towards the east, the bluish shadow projected by the Earth is visible right above the horizon, followed by a light-pinkish band known as the belt of Venus, a phenomenon due to backscattering of reddened light from the rising or setting sun.