LOS ANGELES — Scientists have found the most distant space object yet observed, a galaxy born just 500 million years after the Big Bang.
The discovery, reported Wednesday in the journal Nature, may aid exploration of a crucial period in the early history of the cosmos — a time when light from the earliest stars broke up the fog of hydrogen gas that shrouded the universe shortly after the Big Bang. That process created the “reionized” universe that exists to this day, scientists believe.
“This is one of the most fundamental problems in astronomy — how the universe ionized,” said the study’s lead author, astronomer Matthew Leh nert of the Observatoire de Paris in France.
Lehnert said that while astronomers know reionization occurred, they don’t understand how, because they haven’t been able to observe the process underway. “That’s why (seeing this object) matters,” he said.
The Hubble Space Telescope first spotted the galaxy, named UDFy-38135539, after a new camera that permitted clearer images of distant objects was put on the telescope in May 2009. Analysis showed that light escaping it was emitted more than 13 billion years ago. The light from the farthest galaxy previously detected started the trip to Earth about 150 million years later.
