Formation of Milky Way Galaxy
13.6 Billion years ago · Prehistoric
The Milky Way began forming approximately 13 billion years ago, roughly 800 million years after the Big Bang. ESA's Gaia mission revealed that the thick disk started forming 2 billion years earlier than previously estimated. Around 11 billion years ago, a merger with a smaller galaxy called Gaia-Enceladus triggered a surge in star formation. The galaxy's most productive phase spanned from 13 to 8 billion years ago, with subsequent accretion events shaping the spiral structure containing an estimated 100-400 billion stars.
Key Figures
Immanuel KantThomas WrightJan OortKarl Jansky
Locations
Milky Way GalaxySagittarius A*
Topics
Milky WaySolar Systemstarsgalaxy
Connected Events — 5 Connections
Milky Way's formation preceded and enabled the gravitational assembly of the Local Group Formation of the Local Group Begins
HP 1 is among the oldest surviving structures within the Milky Way, forming in the galactic bulge during the galaxy's earliest epoch Formation of Globular Cluster HP 1 in the Milky Way Bulge
The Gaia-Enceladus collision was the last major merger in the Milky Way's history, fundamentally reshaping the galaxy's halo structure and stellar populations Gaia-Enceladus Dwarf Galaxy Merges with the Milky Way
Balick and Brown's 1974 radio detection of Sgr A* confirmed the supermassive black hole at the center of the Milky Way, revealing the gravitational anchor around which the galaxy formed Discovery of Sagittarius A*
The burst represents a period of elevated star formation within the Milky Way, contributing to the galaxy's stellar mass growth Milky Way Star Formation Burst Recorded in Presolar Grains
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