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

A new study suggests the universe might be slowly rotating, completing a full revolution every 500 billion years. This subtle ...

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

Primordial black holes are the earliest black holes thought to exist, and they vanished almost as fast as they came into ...

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

Scientists analyzed data from 7 million galaxies and stumbled upon a missing piece of the cosmic puzzle. Thanks to the ...

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

A distant galaxy that lay quiet for decades has suddenly stirred, lighting up in dramatic bursts that have caught astronomers ...

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

About half of the non-dark matter in the universe cannot be accounted for by stars and galaxies alone. Now, scientists say ...

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

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