Astronomers have just found an absolute monster of a galaxy.

Lurking some 3 billion light-years away, Alcyoneus is a giant radio galaxy reaching 5 megaparsecs into space. That’s 16.3 million light-years long, and constitutes the largest known structure of galactic origin.

The discovery highlights our poor understanding of these colossi, and what drives their incredible growth. But it could provide a pathway to better understanding, not just of giant radio galaxies, but the intergalactic medium that drifts in the yawning voids of space.