In a study published today in the journal Nature, astronomers from MIT and Arizona State University report that a table-sized radio antenna in a remote region of western Australia has picked up faint signals of hydrogen gas from the primordial universe.
The scientists have traced the signals to just 180 million years after the Big Bang, making the detection the earliest evidence of hydrogen yet observed.
They also determined that the gas was in a state that would have been possible only in the presence of the very first stars. These stars, blinking on for the first time in a universe that was previously devoid of light, emitted ultraviolet radiation that interacted with the surrounding hydrogen gas. As a result, hydrogen atoms across the universe began to absorb background radiation — a pivotal change that the scientists were able to detect in the form of radio waves.
The findings provide evidence that the first stars may have started turning on around 180 million years after the Big Bang.
Continue reading at MIT.
Image via MIT.