Astronomers may have found the long-missing half of the universe's regular matter—and it appears to have been right under our ...

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

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

There’s a point in the universe where no light, no signal, and no matter can reach us — or so we thought. Galaxy clusters are drifting in one direction, as if pulled by something beyond our reality.

Physicist Richard Lieu first explored the idea that gravity could exist without mass—now he’s got a new cosmological model ...

The supposed size limit — 381 kilometers per side — originates from technical constraints within Adobe’s Acrobat reader.

The spins of some early galaxies could be a clue that the entire observable universe exists within a black hole—except, that ...

Experts have unveiled the most detailed images yet of the universe’s infancy, capturing light that traveled for more than 13 ...

Extreme cosmic events such as colliding black holes or the explosions of stars can cause ripples in spacetime, so-called gravitational waves. Their discovery opened a new window into the universe. To ...

The universe doesn't come with an instruction manual—but if it did, University of Missouri Assistant Professor Charles ...