Our Milky Way galaxy never sits still: it rotates and wobbles. And now, data from the European Space Agency’s Gaia space telescope reveal that our galaxy also has a giant wave rippling outwards from its centre.
The unexpected galactic ripple is illustrated in this figure above. Here the positions of thousands of bright stars are shown in red and blue, overlaid on Gaia’s maps of the Milky Way.
In the left image, we look at our galaxy from ‘above’. On the rig... [4085 chars]