Heavyweight galaxies in the young universe

Newfound massive galaxies may force theorists to revisit formation model

Peering into the center of five of the youngest clusters of galaxies known in the universe, astronomers recently found several full-grown, cigar-chomping adults among the myriad of toddlers. The remote galaxies hail from a time when the 13.7-billion-year-old cosmos was less than 5 billion years old. Yet measurements reveal that the bodies are just as massive as galaxies like the modern-day Milky Way, which took at least 10 billions years to mature.