How many galaxies are in the universe?

Deep images from the Hubble Space Telescope, such as the Hubble Ultra Deep Field, revealed thousands of galaxies in a patch of sky smaller than a grain of sand held at arm’s length. Extrapolating across the whole sky gave early estimates of around 100 to 200 billion galaxies. A 2016 study suggested there could be up to 2 trillion if faint, small galaxies are counted, but later measurements of background light from the New Horizons spacecraft pointed back toward hundreds of billions. The James Webb Space Telescope continues to find very distant galaxies. The whole universe beyond what we can observe may be far larger.