A new study led by astronomers from Durham University suggests that the Milky Way galaxy experienced a dramatic 'flipping' event billions of years ago after a collision with a smaller galaxy. The research, published in the Monthly Notices of the Royal Astronomical Society, used data from the Gaia space telescope to trace the motion of stars in the galactic disk.
The team found evidence that the Milky Way's disk tilted and inverted around 13 billion years ago, likely due to a merger with a dwarf galaxy named Gaia-Enceladus. This event may have altered the Sun's orbit and the structure of the galaxy we see today.
Dr. Robert Grand, lead author from Durham University, stated: 'This is a major step in understanding how our galaxy formed. The collision not only flipped the disk but also changed the paths of stars, including our own Sun.' The findings help explain the distribution of old stars in the Milky Way's halo.
