Death by Laser?

At first glance, this image looks both awesome and intimidating, with the enormous beams of light resembling some terrible cosmic weapon. Fortunately, that is not the case! This ESO Picture of the Week shows something far more benign — a mixture of gas, dust, and powerful lasers.

Among the largest nebulae in the southern night sky, the Carina Nebula is a perfect viewing target for ESO’s Very Large Telescope (VLT). In this image, the nebula appears as a stunning pink cloud in the clear sky above ESO’s Paranal Observatory in Chile, home of the VLT. The Carina Nebula is a vast cloud of dust and gas — this gas is ionised and made to glow by the stars within the nebula itself. 

The cutting-edge Adaptive Optics Facility installed on one of the 8.2-metre Unit Telescopes (UTs) of the VLT is in full operation here. The orange laser beams are sent from the UTs into the atmosphere where they excite sodium particles, causing them to glow. This creates artificial ‘stars’ that can be used to measure the blurring effects caused by Earth’s atmosphere, which are then corrected by the telescope.