Eerie Discovery of 2 'Identical' Galaxies in Deep Space Is Finally Explained - ScienceAlert

Now, they've finally solved the mystery of these strange "identical objects" – and the answer could have implications for understanding dark matter.

The object, now named Hamilton's Object, was discovered by astronomer Timothy Hamilton of Shawnee State University by accident, in data obtained by the Hubble Space Telescope nearly a decade ago.

The two galaxies appeared to be the same shape, and had the same nearly parallel dark streaks across the galactic bulge – the central region of the galaxy where most of the stars live.

This made a lot more sense than two identical galaxies, especially when Griffiths found yet another duplication of the galaxy (as can be seen in the picture below).

Between us and Hamilton's Object lurks a cluster of galaxies that had only been poorly documented.

The team's work revealed that Hamilton's Object is around 11 billion light-years away, and a different team's work revealed that that the cluster is about 7 billion light-years away.

Computer simulations then helped determine that the three duplicated images could only be created if the distribution of dark matter is smooth at small scales.

The two identical side-by-side images were created because they straddle a "ripple" in space-time – an area of greatest magnification created by the gravity of a filament of dark matter.