Author: Sandro Tacchella, Assistant Professor in Astrophysics, Kavli Institute for Cosmology, Cambridge, Department of Physics, University of Cambridge

The James Webb Space Telescope (JWST) is the largest and most powerful space telescope built to date. Since it was launched in December 2021 it has provided groundbreaking insights. These include discovering the earliest and most distant known galaxies, which existed just 300 million years after the Big Bang. Distant objects are also very ancient because it takes a long time for the light from these objects to reach telescopes. JWST has now found a number of these very early galaxies. We’re effectively looking back in time at these objects, seeing them as they looked shortly after the birth of…