The Universe began in a burst of light nearly 14 billion years ago, but as it expanded and cooled, darkness set in. Today, ...

For hundreds of a millions of years, the universe existed in the dark ages—an epoch when only primordial gasses existed. Then, a period of reionization, cleared away this foggy existence an introduced ...

There is physically, absolutely zero way that we will ever know how large the universe is,” says Sara Webb, an astrophysicist at Swinburne University of Technology. Yet what astronomers can measure is ...

Over billions of years, the universe's stars and galaxies shined their light into space, leaving behind an imperceptibly faint night light known as the cosmic optical background. NASA's New Horizons ...