Milky Way grew by devouring galaxies, leaving ghost stars behind
Astronomers use the chemical composition and motion of star clusters to reconstruct the history of the Milky Way over 12 billion years.
The Milky Way galaxy grew by consuming other galaxies, leaving behind trails of stars that do not move in sync with the rest of the galaxy, according to The Hindu.
These 'ghost stars' are left behind when smaller galaxies are ripped apart by the tidal forces of larger ones during collisions.
Modern astronomers identify these smaller galaxies as the Small and Large Magellanic clouds, which are currently being swallowed by the Milky Way.
Galactic archaeologists use the age, chemical composition, and motion of these stars to understand the evolution of the galaxy.
By studying these minute differences in star groups, scientists can piece together the history of the Milky Way going back almost 12 billion years.