(Image: Arnaud Borde CEA/IRFU 2013)

Is this a satellite shot of a country at night, lit up by glittering cities? Or perhaps a collection of raving microbes, pulsing to a neon rhythm? Nope, it’s a 600-billion-billion-kilometre-wide chunk of the universe – or at least a simulation of it.

Astronomers working on the Baryon Oscillation Spectroscopic Survey (BOSS) are attempting to map galaxies and hydrogen gas clouds in the universe by looking for the light of super-bright quasars, luminous objects that are thought to be powered by black holes devouring matter. Galaxies and gas clouds leave an imprint on this quasar light as it passes through them, which can be used to deduce their positions.

To make sense of these imprints, the BOSS team create simulations of quasar light passing though cosmos-spanning gas clouds and compare them with the real thing. The picture above shows a simulation of a cube of the universe 65 million light years across. The red blobs are clusters of galaxies, while the blue filaments show regions of low-density filled with clouds of gas.