Astronomers have discovered an unexpected cache of spiral galaxies that appear to have formed recently, long after the period early in the history of the universe that most galaxies were thought to have been created.
These younger galaxies are big and bright, like our own Milky Way. The reigning hypothesis of galaxy formation holds that such well-established spirals would have formed about 13 billion years ago, shortly after the Big Bang.
But the new discovery of a group of 15 spirals that look to be much younger may upset that thinking.
More: http://www.space.com/scienceastronomy/090428-st-young-galaxies.html (http://www.space.com/scienceastronomy/090428-st-young-galaxies.html)