Guide star lasers at sunset

This captivating images shows the beam of light from the Very large Telescope (VLT) 4 Laser Guide Star Facility against the rare sight of a cloudy sunset at Paranal Observatory, Chile.

The lasers, which are the most powerful laser guide stars ever used for astronomy, are an integral part of the adaptive optics system on the VLT. Adaptive optics allows astronomers to drastically reduce the atmospheric distortion present at even the best sites in the world for astronomy, including Paranal.