Studying the Milky Way presents a significant challenge for astronomers, as it becomes increasingly difficult to determine past events the deeper we look back in time. However, thanks to the Hubble Space Telescope, new data about the evolution of our galaxy has been obtained.

In its early stages, the Milky Way was much smaller and resembled the young galaxies observed throughout the Universe. During this period, the galaxy exhibited chaotic behavior and frequently merged with other galaxies.

To analyze this stage, astronomers used the Hubble telescope to observe 39 globular clusters within the Milky Way. These clusters, each containing hundreds of thousands of stars, can have different origins. It is believed that some of them formed from structures that later merged with our galaxy.

Thanks to the high resolution and depth of the images captured by Hubble, as well as data from the Gaia mission, researchers were able to determine the age and chemical composition of these clusters with great accuracy. This allowed them to identify a distinct population of globular clusters that differ from the rest.

The results showed that these clusters originated from a galaxy named Low-energy-Kraken-Heracles, whose stellar mass was about 500 million solar masses. The merger of this galaxy with the Milky Way occurred approximately 12.3 billion years ago.

Galaxy mergers are a common phenomenon in the Universe. The Milky Way has already merged with other galaxies, including Gaia-Sausage-Enceladus about 10 billion years ago, which led to changes in its shape and structure.