Scientists have made an incredible discovery about our very own galaxy: a giant spinning halo that could shed light on how the galaxy was formed. This halo of super-hot gas surrounds our galaxy entirely and rotates almost as fast as us, scientists believe. And that’s not all that’s interesting about this phenomenon.

This halo is hundreds of thousands of light years thick and could help explain why there is not as much matter in the Milky Way as scientists would have expected. But the fact htat it’s spinning at almost the same rate as the rest of the galaxy is what’s really fascinating to scientists.

Scientists at the University of Michigan used changes in light wavelengths to measure how fast the halo was spinning, according to NASA/Goddard Space Flight Center statement. They found that hte halo was spinning int he same direction as the Milky Way’s stellar disc at a speed of 400,000 miles per hour.

Scientists say this wasn’t expected. Most had assumed that the halo of hot gas was stationary with the galaxy spinning in between it, but that’s turned out to be incorrect.

And it may help scientists understand how the galaxy formed billions of years ago: the finding could indicate that it is the original source of a lot of matter in the galaxy.

“This flies in the face of expectations,” says Edmund Hodges-Kluck, assistant research scientist. “People just assumed that the disk of the Milky Way spins while this enormous reservoir of hot gas is stationary – but that is wrong. This hot gas reservoir is rotating as well, just not quite as fast as the disk.

“The rotation of the hot halo is an incredible clue to how the Milky Way formed,” he continued. “It tells us that this hot atmosphere is the original source of a lot of the matter in the disk.”