Images from the Webb telescope confirm the oldest galaxies ever seen

Scientists have confirmed that observations made in 2022 are of the oldest galaxies ever seen, according to two papers based on images and spectroscopic analysis of data from the James Webb Space Telescope (JWST) and published in Nature Astronomy.

The four galaxies dating to when the Universe was around 300–500 million years old, or about 2 percent of its current age, were smaller and much more compact than today's galaxies, including our own Milky Way. The four galaxies "were also in their infancy, compared to the Milky Way," says astronomer Stefano Carniani, of the Scuola Normale Superiore in Pisa and author, together with Emma Curtis-Lake of the University of Hertfordshire, of one of the papers . These ancient galaxies were still poor in complex elements, such as carbon, oxygen and nitrogen, the scientists found.

In the same issue of the journal, a companion paper by Brant Robertson of the University of California at Santa Cruz and Switzerland’s Sandro Tacchella of the University of Cambridge provides other characteristics of the galaxies, determining their size and indicating that the stars contained in each of them had a total mass equal to 100 million times that of our Sun.