Overview

• ESA's Gaia spacecraft has mapped the motions of over a billion stars, revealing unexpected patterns.
• The study suggests a major merger event happened three billion years ago, not eight to eleven billion years ago as previously believed.
• The collision involved a massive dwarf galaxy, bringing in stars that now exhibit unusual orbits.
• This finding challenges long-held models of the Milky Way's formation and growth.
• Future research will explore the implications of this more recent merger on our galaxy's evolution.