The Milky Way devoured a smaller galaxy about 11.8 billion years ago - Reuters

“Astronomers have identified evidence that the Milky Way swallowed a dwarf galaxy roughly 11.8 billion years ago, a period shortly after the universe’s first major star‑forming epoch. Using data from the Gaia mission and Hubble Space Telescope, researchers traced a distinct stream of ancient stars whose chemical fingerprints differ from native Milky Way populations, confirming a massive accretion event. This discovery refines our timeline of the Galaxy’s growth and helps calibrate models of how large galaxies assemble over cosmic time. Expert Analysis: The finding underscores the importance of galactic archaeology for improving simulations that drive aerospace and satellite‑orbit predictions—sectors critical to the U.S. defense and commercial space industries. As models become more precise, they can inform better risk assessments for satellite constellations operating in increasingly crowded orbital environments.”