In this image astronomers are seeing an embryonic cluster as it was when the universe was 1.5 billion years old. The young system, called TNJ1338-1942, is the most distant known proto-cluster. It is dominated by a massive baby galaxy - the green object in the centre. The galaxy is producing powerful radio emissions, and is the brightest galaxy in the proto-cluster. The green colour indicates that the galaxy is emitting glowing hydrogen gas. Click to enlarge.
