In the grand puzzle of the cosmos, one question continues to defy easy answers: how fast is the universe expanding?

"What makes Zhúlóng stand out is just how much it resembles the Milky Way—both in shape, size and stellar mass," said the ...

Researchers have spent the past few years watching a black hole re-awaken roughly 300 million light-years away from Earth.

New research has revealed that the cosmological model developed by Nicolaus Copernicus, the renowned European Renaissance ...