On 27 October, the Hubble Space Telescope photographed two galaxies more than 400 million light-years from Earth. This is only one in a long line of photographed galaxies, but what makes this picture especially interesting is that the shape of the galaxies suggests an unimaginably large collision took place quite recently, i.e. only a few billion years ago. Scientists think the ring of stars was formed after the galaxy on the left passed through the galaxy on the right.

(Image by NASA and ESA.)