Abstract

The successful launch, deployment and commissioning of the James Webb Space Telescope has opened a new era in astronomy and astrophysics. Indeed, in some infrared spectral bands, Webb’s sensitivity is up to three orders of magnitude higher than previous facilities. Such a huge leap in sensitivity has happened very rarely in the history of astronomy and, even more broadly, in the history of science. To put it into a context, it is equivalent, in the visible, to suddenly passing from Galileo’s telescope to modern 10m-class telescopes. The first observations released by this fantastic observatory have not disappointed, by delivering several unexpected results.

I will give an overview of the early, exciting Webb’s findings by focusing on the new results on distant galaxies. I will show that some of these discoveries are drastically changing our understanding of galaxy formation in the early Universe and of their subsequent evolution across the cosmic epochs.

However, I will also emphasise that this is just the beginning: the truly revolutionary results are expected to come next year, when the new classes of galaxies discovered by Webb will be characterised via deep spectroscopic follow-up.