A Telescopic Quartet

Far from civilisation, deep in the barren, mountainous terrain of Chile’s Atacama Desert, stand four pillars of modern astronomy: the enormous and angular enclosures of the Unit Telescopes (UTs) of ESO’s Very Large Telescope.

The Sun’s diffuse orange glow peeking over the horizon is no match for the light display filling the sky above. Containing hundreds of billions of stars, the great bow of the Milky Way stretches across the panorama, dipping down to touch the horizon. The mottled look of our home galaxy is due to huge clouds of interstellar dust obscuring more distant starlight. Bright stars, celestial objects, and other phenomena in our cosmic neighbourhood hang like lanterns in the Chilean sky, backlit by ethereal red and green airglow.

Alone, each UT can make magnificent observations of the Universe from their home at ESO’s Paranal Observatory — but the four telescopes can also work together and observe the cosmos as a quartet, producing a telescope with an effective mirror diameter of up to 130 metres.