{"id":591455,"date":"2026-08-21T10:18:14","date_gmt":"2026-08-21T10:18:14","guid":{"rendered":"https:\/\/www.newsbeep.com\/il\/591455\/"},"modified":"2026-08-21T10:18:14","modified_gmt":"2026-08-21T10:18:14","slug":"our-galaxy-swallowed-another-galaxy-shortly-after-the-big-bang-and-scientists-just-found-the-smoking-gun","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/il\/591455\/","title":{"rendered":"Our Galaxy swallowed another galaxy shortly after the Big Bang. And scientists just found the smoking gun"},"content":{"rendered":"

Our home Galaxy the Milky Way wasn’t always been a majestic spiral galaxy containing of hundreds of billions of stars and dark matter.<\/p>\n

Instead, it grew over time into the cosmic giant we know today through a bouts of galactic cannibalism lasting billions of years.<\/p>\n

Yes, our Galaxy has spent most of its existence swallowing smaller neighbouring dwarf galaxies and adding their stars, gas and dark matter to its own collection.<\/p>\n

Now, a new study using the Hubble Space Telescope has found proof of a previously unknown galactic merger that occurred just after the Big Bang, early in the history of the Universe.<\/p>\n

\"Artist'sCredit: Mark Garlick \/ Science Photo Library \/ Getty Images<\/p>\n

Meet the Low-energy-Kraken-Heracles merger<\/p>\n

The newly-discovered, early victim of the Milky Way’s wrath is a dwarf galaxy named Low-energy-Kraken-Heracles, or LKH for short.<\/p>\n

The merger amount to our Milky Way swallowing stars equivalent to a mass 500 million times that of our own Sun.<\/p>\n

This occurred about 11.8 billion years ago, just 2 billion years after the Big Bang<\/a>.<\/p>\n

And because the young Milky Way was so much smaller than it is today, absorbing LKH contributed a massive chunk of our galaxy’s total weight at the time.<\/p>\n

\"\"Artist’s impression of the LKH Milky Way merger 11.8 billion years ago. Credit: NASA, ESA, Joseph Olmsted (STScI)
\nNot our first galactic meal<\/p>\n

The consumption of the Low-energy-Kraken-Heracles dwarf galaxy is not the only galactic meal our Milky Way has enjoyed throughout its 13.6-billion-year-old history<\/a>.<\/p>\n

Astronomers already know about the most recent merger, when the Milky Way swallowed the Sagittarius dwarf galaxy about 6 billion years ago. That merger is still ongoing today.<\/p>\n

10 billion years ago, the Milky Way galaxy consumed another dwarf galaxy called Gaia-Sausage-Enceladus.<\/p>\n

Astronomers say that ancient merger significantly affected the structure of our galaxy\u2019s disk of stars.<\/p>\n

Other smaller mergers are known to have occurred between those two.<\/p>\n

Milky Way merger
\nTime period<\/p>\n

Low-energy-Kraken-Heracles
\n11.8 bn years ago<\/p>\n

Gaia-Sausage-Enceladus
\n10 bn years ago<\/p>\n

Sagittarius dwarf galaxy
\n6 bn years ago<\/p>\n

\"\"Artist\u2019s impression of the Gaia-Enceladus merger with the Milky Way, 10 billion years ago. Positions and motions of the stars in Gaia-Enceladus are shown with yellow arrows. Credit: ESA (artist\u2019s impression and composition); Koppelman, Villalobos and Helmi (simulation); NASA\/ESA\/Hubble (galaxy image)
\nHow they made the discovery<\/p>\n

If our Galaxy has been evolving for 13.6 billion years, how is it possible to know that it swallowed a small galaxy 11.8 billion years ago?<\/p>\n

Over billions of years our Galaxy’s stellar motions have become perturbed, erasing the obvious shapes of devoured galaxies. So making the discovery required a lot of cosmic detective work.<\/p>\n

The study’s lead author Davide Massari, of the Astrophysics and Space Science Observatory of Bologna, Italy, and his team used the Hubble Space Telescope to effectively look back in time.<\/p>\n

The team used Hubble data to study 39 different globular clusters. These are densely packed clusters of up to millions of ancient stars, all held together by gravity.<\/p>\n

Globular clusters<\/a> are among the oldest objects in the Universe.<\/p>\n

\"GlobularGlobular cluster NGC 6426. These ancient star clusters are among the oldest objects in the Universe. Credit: NASA, ESA, and A. Dotter (Dartmouth College). Image processing: Gladys Kober (NASA\/Catholic University of America)<\/p>\n

By measuring the precise age and metallicity \u2013\u00a0chemical fingerprints \u2013\u00a0of these clusters, researchers sorted the sample into distinct groups:<\/p>\n

Native clusters born inside the young Milky Way
\nThe 10-billion-year old group of clusters absorbed when the Milky Way consumed the Gaia-Sausage-Enceladus dwarf galaxy
\nA newly-identified, third population of clusters<\/p>\n

This third group of clusters are older than those from Gaia-Sausage-Enceladus, but younger than the Milky Way’s native clusters.<\/p>\n

That, say the team, proves they came from a separate, earlier galactic merger.<\/p>\n

\"ThisArtist\u2019s impression of our galaxy, the Milky Way, based on data from ESA\u2019s Gaia space telescope. Credit: ESA\/Gaia\/DPAC, Stefan Payne-Wardenaar
\nWhy this changes the story of the Milky Way<\/p>\n

For a long time, astronomers debated whether the infant Milky Way was a quiet, self-contained galaxy where stars only formed from internal gas clouds, or whether external forces like galaxy mergers played an active role.<\/p>\n

The discovery of the Low-energy-Kraken-Heracles shows our Galaxy was consuming smaller galaxies from the beginning \u2013 and that external galactic building blocks were essential to laying the foundation of our cosmic home.<\/p>\n

“Our home is the Milky Way galaxy, but we do not know how our house was built,” says Massari.<\/p>\n

“In this paper we discover where the first significant batch of bricks came from: a dwarf galaxy that we call LKH.”<\/p>\n

Read the full paper via Nature Astronomy<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"Our home Galaxy the Milky Way wasn’t always been a majestic spiral galaxy containing of hundreds of billions…\n","protected":false},"author":2,"featured_media":591456,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[85,46,141,145],"class_list":["post-591455","post","type-post","status-publish","format-standard","has-post-thumbnail","category-space","tag-il","tag-israel","tag-science","tag-space"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/591455","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/comments?post=591455"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/591455\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media\/591456"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media?parent=591455"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/categories?post=591455"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/tags?post=591455"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}