BEIJING, March 1 (Xinhua) -- Astronomers have for the first time detected signals of light from the earliest stars in the our universe, according to a study published on Nature on Wednesday.
Scientist had long suspected the earliest stars in our universe came to be about 100 million years after the Big Bang. But they never had the evidence to back it up until now. Before this new study, the oldest stars ever found dated to about 400 million years after the Big Bang.
"This is the first time we've see any signal from this early in the Universe, aside from the afterglow of the Big Bang," said Judd Bowman, an astronomer at Arizona State University in Tempe who led the study.
Physicists believed that our universe was dark, hot and full of high-energy particles. After 370,000 years, this soup began to form neutral hydrogen atoms. Over time, they were pulled together by gravity and formed stars that ignited. This is also known as the cosmic dawn.
The earliest star lights, astronomers theorized, would have heated up the hydrogen gas permeating the universe, which would be reflected in the cosmic microwave background.
However, this is only theory. The changes on the cosmic microwave background were so subtle that they could be easily overwhelmed by radio signals produced by human activities.
Scientists have spent decades finding the evidence until Bowman's team used a relatively small antenna in an Australian dessert to pick the right signal.
