Explore galaxy formation, the scientific study of how galaxies—vast collections of stars, gas, dust, and dark matter—emerge and evolve across cosmic time. This...
Galaxy formation is the astrophysical process describing how galaxies, immense cosmic islands of stars, gas, dust, and dark matter, coalesce and evolve from initial density fluctuations in the early universe.
Dark matter is crucial. Its gravitational pull creates invisible 'halos' that act as gravitational scaffolds, attracting ordinary matter (gas and dust) to collect and form stars and, subsequently, galaxies.
Galaxies evolve through internal processes like star formation and gas cycling, but also significantly through interactions and mergers with other galaxies, which can drastically alter their size, shape, and composition.
The first galaxies are believed to have started forming relatively early, only a few hundred million years after the Big Bang, as matter cooled and gravity pulled it together within dark matter halos.