When our universe was born, the meeting of matter and antimatter should have annihilated each other. That means that nothing—no Earth, no sun, no galaxies, no humans—would exist. But we do.

A new theory about a sphere-shaped universe contradicts the conventional idea that the universe stretches infinitely in all directions.

Researchers are closer than ever to detecting a signal from a time when the first stars in the universe emerged from the "cosmic dark ages."

What does the universe look like? Get the answer to this and other spacey questions straight from the experts in this video.

Exactly what dark matter is and how it came to be is still a mystery, but new calculations could add to our understanding of its origins.

The star may be from one of the first generations in the universe and suggests our galactic neighborhood could be billions of years older than we thought.