By Ron Cowen
This winter has been one of the hottest on record for cosmologists. A flurry of new reports suggests that a surprising number of galaxies grew up in a hurry, appearing old and massive even when the universe was still very young. If this portrait of precocious galaxies is confirmed by larger studies, astronomers may have to revise the accepted view of galaxy formation. The provocative reports started pouring in just before Christmas. In mid-December, scientists announced in a press release that they had found a group of distant galaxies that were already senior citizens, chockablock with elderly, red stars a mere 2 billion years after the Big Bang. The same team found another surprise: Some of those galaxies were nearly as large as the largest galaxies in the universe today.
On Jan. 7, another team posted an online report asserting it had found the oldest, and therefore most distant, galaxy known. If confirmed, the study indicates that some galaxies were in place and forming stars at a prolific rate when the universe, now 13.7 billion years old, was just an 800-million-year-old whippersnapper.