Durham astronomers say Milky Way flipped 10-11 billion years ago
Turns out, our Milky Way might have done a dramatic flip about 10 to 11 billion years ago!
Astronomers from Durham University say a smaller galaxy, Gaia-Sausage-Enceladus, crashed into us, tipping the whole spiral disk by more than 90 degrees.
This cosmic shake-up could explain why the ancient stars in our galaxy's halo move so slowly.
Supercomputer simulations show collisions scatter stars
Using supercomputer simulations of galaxies like ours, researchers found that big collisions like this not only tilt the disk but also toss stars into stretched-out orbits, maybe even changing where the Sun travels.
They also discovered that our slow-spinning stellar halo moves in sync with nearby dark matter, hinting that both evolved together during these wild early days.
All this helps scientists piece together how galaxies (and dark matter) grow and change over time.