Andromeda’s Orbiting Dwarf Galaxies – “Point to Something Profound”
A string of 13 dwarf galaxies in orbit around the massive galaxy Andromeda –remnants of the population of primordial structures that coalesced to form giant galaxies like the Milky Way–are spread across a flat plane more than one million light years wide and only 30,000 light years thick –a distance so vast that they have yet to complete a single orbit. The 2016 discovery suggests that conventional ideas regarding the formation of galaxies are missing something fundamental.