Produced by: Tarun Mishra Designed by: Manoj Kumar
Galaxies, including our own Milky Way, formed billions of years ago. The James Webb Space Telescope allows us to look back at some of the first galaxies in the early universe. But are galaxies still being born today?
Galaxies are large collections of stars, gas, and dark matter. Typically, they are easy to identify and distinguish from one another, similar to towns separated by larger distances.
Galaxies emerged through a gradual process beginning shortly after the Big Bang. Tiny pockets of higher density grew, pulling in dark matter first, then regular matter, leading to the formation of the first stars and protogalaxies.
Today, the process of creating new galaxies from initial density differences or dark matter gathering is over. There are no more protogalaxies or clouds of gas waiting to form new galaxies.
If we define a galaxy by the appearance of its first stars, new galaxies are still being formed. Star formation is an ongoing process, contributing to the creation of new galaxies even in the present-day universe.
Astronomers have observed that the number of small, medium, and large galaxies has increased over time. This is due to existing clumps of material beginning star formation and the merger of smaller galaxies into larger ones.
Star formation is inefficient, with most gas in a galaxy never turning into stars. This allows star formation to continue for long periods, giving galaxies a long time to get started.
The universe's expansion is accelerating due to dark energy, making it harder for material to clump together to form new galaxies. The peak of star formation occurred billions of years ago, and the rate of new galaxy formation is slowing down.
While new galaxies continue to appear, their emergence is decreasing. Star formation will continue for hundreds of billions of years, but the number of new galaxies will gradually decline. Enjoy the cosmic display while it lasts.