New generation. As this artists' conception shows, young galaxies (right) are glaringly bright compared to older ones (left) in ultraviolet wavelengths. Credit: Nasa/Jpl-Caltech
The Galaxy Evolution Explorer (GALEX) has returned snapshots of several dozen newborn galaxies, (...). Remarkably, these objects are nearby, not many billions of light-years away as all other known baby galaxies are. This closeness will give scientists a brand new way to study how galaxies formed.
Astronomers have long known that most galaxies coalesced when the universe was young; their birthrate peaked about five billion to ten billion years ago and has been declining ever since.