NASA reported on Aug. 17, 2026, that data from the Hubble Space Telescope show definitive evidence of a dwarf galaxy merging with the young Milky Way in its earliest phases of evolution. The agency said the finding extends knowledge of the galaxy's history 1.8 billion years farther back in time than before, and that the results were published in Nature Astronomy.

The dwarf galaxy, named Low-energy-Kraken-Heracles, or LKH, merged with the Milky Way about 11.8 billion years ago, roughly 2 billion years after the big bang, according to the report. The team analyzed Hubble observations of 39 globular clusters within the inner 20,000 light-years of the galaxy and identified a third population of clusters older than those linked to the Gaia-Sausage-Enceladus merger but younger than those born in the Milky Way.

The source states LKH contained roughly 500 million times the mass of the Sun in stars. Lead author Davide Massari of the Astrophysics and Space Science Observatory of Bologna said the paper identifies where the first significant batch of building material came from. The team planned to continue studying globular clusters to characterize the galaxy's massive mergers.