{
  "id": 12915262,
  "title": "The Milky Way is one galaxy — but it used to be thousands, new simulations reveal",
  "url": "https://urgent.news/2026/10/08/the-milky-way-is-one-galaxy-but-it-used-to-be-thousands-new",
  "topic": "science",
  "section": "Science",
  "published": "2026-10-08T17:40:51.000Z",
  "source": {
    "name": "Live Science",
    "slug": "live-science",
    "url": "https://www.livescience.com/space/astronomy/the-milky-way-is-one-galaxy-but-it-used-to-be-thousands-new-simulations-reveal"
  },
  "original_language": "en",
  "account": "New research reveals that the Milky Way, once a collection of thousands of small galaxies, underwent a process of merging to become the spiral galaxy we know today. This transformation occurred in the first 2 billion years following the Big Bang, during which the region where our galaxy now resides was filled with numerous galaxies of varying sizes and shapes. The simulation, conducted using a suite of supercomputer models called Megatron, provides a detailed tracing of this cosmic evolution. Megatron was built to bridge the gap between current computer models and the unexpected discoveries made by the James Webb Space Telescope (JWST). JWST's observations have revealed surprisingly bright early galaxies and a new class of compact galaxies called Little Red Dots, which challenge existing models. By comparing the simulation with JWST observations and analyzing the chemical traces in ancient stars, scientists can better understand the formation of these first stars and their impact on the surrounding environment. The simulation begins 180 million years after the Big Bang, when the universe contained only pristine gas, and progresses through the formation of the first stars, their violent deaths, and the spread of heavy elements that would eventually give rise to future stars and planets. As the simulation concludes 2 billion years after the Big Bang, it also highlights the continued mergers that have shaped the Milky Way over time. The researchers involved in the study, including Harley Katz and Martin Rey, emphasize that while the simulation provides valuable insights into the early universe, there are still gaps that need to be addressed. They are now developing more advanced simulations that incorporate additional complex physics, such as the influence of active black holes, which JWST has shown to be prevalent in the early cosmos.",
  "summary": "A new supercomputer simulation traces how thousands of small galaxies eventually became the Milky Way.",
  "key_points": [
    "Milky Way was once thousands of small galaxies that merged",
    "Simulation using Megatron traces cosmic evolution over 2 billion years",
    "JWST observations challenge existing models of early galaxies"
  ],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}