Cosmic Magnifying Lens Unveils Oldest Galaxy
Scientists have discovered the strongest evidence yet for a 13.2-billion-year old galaxy, a finding that provides a key piece of information about the universe’s early childhood. “This is the most distant (galaxy) identified with high confidence,” astronomer Wei Zheng, with Johns Hopkins University, told Discovery News. “If our current universe is a man of 70 years of age, we have reached an ‘infant’ of 2.5-years young,” Zheng wrote in an email. “It is like an archaeologist finding an oldest piece in history.”
From the cosmic microwave background radiation, scientists figure that the universe began about 13.7 billion years ago. It evolved quickly. By the time the universe was 1.4 billion years old, it not only was filled with galaxies, but the hydrogen gas between the galaxies had become highly ionized. The universe’s baby steps to reach this stage are largely missing from the picture, primarily because telescopes to image objects back that far in time are still in the planning stages. But Zheng and colleagues found another way.