Here’s some knowledge that will make you feel like a microbe: Our Milky Way galaxy, a collection of hundreds of billions of stars and worlds, is but a tiny nucleus buried deep inside an enormous blob of million-degree gas that’s spinning at a rip-roaring 644,000km per hour.
Artist’s concept of the giant blob of spinning gas that envelops our galaxy and from which we all emerged. Image: NASA/CXC/M.Weiss/Ohio State/A Gupta et al
Astronomers have known for some time that our galaxy is nestled inside a halo of diffuse, star-forming material called plasma. But until now, it’s been assumed that this extra-galactic plasma is stationary. Not so, according to a new University of Michigan-led study, which used archival data from the European Space Agency’s XMM-Newton telescope to measure how light from the halo is bent and distorted over the millions of light years it travels to reach our eyes.
By examining shifts in the wavelength of very hot oxygen atoms, the researchers were able to show that our galactic halo is not only spinning, it’s spinning insanely fast, and in the same direction as the Milky Way itself.
And that gives us a major clue as to how our galaxy formed. As lead study author Edmund Hodges-Kluck put it in a news release, “It tells us that this hot atmosphere is the original source of a lot of the matter in the disk.”
By continuing to study the great Mother Blob, astronomers hope to learn more about how matter entered the tiny, star-filled embryo of a galaxy we call home over cosmic time. Of course, they will eventually discover that our galaxy, blob and all, is nothing more than a wee marble in a giant sac of marbles belonging to a frighteningly whimsical, god-like reptile… but I’ll let the experts work that one out on their own.