Astronomers spotted a faint glimmer of infrared light from this primitive galaxy, called UDFy-38135539, using the European Southern Observatory's Very Large Telescope in Chile.

Because of the time it takes for the distant galaxy's light to reach Earth, the recently captured signal is thought to have been emitted when the universe was only 600 million years old. That means the find can help scientists better understand the so-called era of reionization, the study authors say.

For about the first billion years after the big bang, the universe was filled with an opaque fog of neutral hydrogen. As the very first stars and galaxies formed out of this fog, their radiation charged any nearby