Astronomers have spotted the biggest pair of black hole jets ever seen, spanning 23 million light-years in total length. That’s equivalent to lining up 140 Milky Way galaxies back to back.

“This pair is not just the size of a solar system, or a Milky Way; we are talking about 140 Milky Way diameters in total,” says Martijn Oei, a Caltech postdoctoral scholar and lead author of a Nature paper reporting the findings. “The Milky Way would be a little dot in these two giant eruptions.”

The jet megastructure, nicknamed Porphyrion after a giant in Greek mythology, dates to a time when our universe was 6.3 billion years old, or less than half its present age of 13.8 billion years. These fierce outflows—with a total power output equivalent to trillions of suns—shoot out from above and below a supermassive black hole at the heart of a remote galaxy.