In a fascinating discovery, astronomers have pieced together clues from over 13 billion years ago to uncover what could be the earliest constituents of our Milky Way Galaxy. Named ‘Shiva’ and ‘Shakti’, these ancient galactic remnants provide a glimpse into how our home galaxy first took shape.
Analyzing intricate star patterns and chemical signatures preserved since the cosmic dawn, scientists at the renowned Max Planck Institute for Astronomy believe they have detected signs of the two progenitor galaxies that collided and merged to seed the growth of the young Milky Way. According to researcher Khyati Malhan, stars within our galaxy still retain tell-tale signs linking them to either ‘Shiva’ or ‘Shakti’ based on their conserved energy and rotational motions from that initial galactic merger epoch.
By combining data from the precise star maps of ESA’s Gaia satellite with chemical abundance information from the Sloan Digital Sky Survey, astronomers picked out distinct overdensities of metal-poor stars clustered around two distinct sets of angular momentum and orbital energies. This suggested these stars originated from two separate galactic progenitors before their collision and accretion onto the primordial Milky Way over 12 to 13 billion years ago.
In a flash of cosmic creativity, Malhan named these long-lost building blocks ‘Shiva’ and ‘Shakti’, representations from Hindu mythology of the divine couples whose dance sustains creation. Their chance merging is thought to have ignited a burst of new star formation while seeding the first extrinsic building blocks to our home galaxy in its formative years. Much like finding relics of an early human settlement that ultimately amalgamated into a vast metropolis, this discovery provides a glimpse into how our own Milky Way may have grown from such ‘galactic collisions and mergers’ in the distant past.
