The 'Fireflies' of the Early Cosmos
Astronomers have detected luminous clusters of galaxies much earlier in the universe’s history than expected.
Close to the beginning of time, not long after the Big Bang, cosmic construction was booming. Giant clumps of gas collapsed under their own weight and formed the first stars. Eventually, galaxies emerged, tugged into glittering arrangements by gravity. Some of them clustered together.
This process took many millions of years to unfold, but thanks to some very powerful telescopes, we now have a mesmerizing snapshot of the events.
Astronomers have detected the light coming from two clusters rich with individual galaxies. Their observations show the two clusters as they were
