Astronomers have long struggled with a troubling puzzle: a significant portion of normal matter in the universe appeared to ...

A new analysis of the sky has finally confirmed where the missing half of the Universe's visible matter has been hiding.

Astronomers tallying up all the normal matter—stars, galaxies and gas—in the universe today have come up embarrassingly short ...

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

A new approach suggests that a tiny spin of the universe throughout space might reconcile those conflicting numbers. If the ...

"We've always known that we need something to complete the puzzle, but we haven't really known what shape or form those ...

Mysterious dark matter makes up 85 percent of matter in the universe, and of the remaining 15 percent, scientists couldn’t ...

The halo is more extended that astronomers originally thought, and contains enough hydrogen gas to resolve the problem of the ...

A slowly spinning universe could resolve a puzzle in physics known as the Hubble tension, a new model suggests.

For decades, scientists have known that ordinary matter — everything made of atoms — accounts for just 15% of the universe’s ...

Dark matter is hypothesized to outweigh "ordinary matter" in the universe by a factor of five. That means all the stuff we ...

Could the universe be rotating? Discover how this theory may solve the Hubble tension in modern cosmology and physics.