For decades, scientists have known that ordinary matter — everything made of atoms — accounts for just 15% of the universe’s matter. The rest is mysterious dark matter. But even that modest slice didn ...

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

“The cosmic microwave background is in the back of everything we see in the universe. It’s the edge of the observable universe. So you can use that as a backlight to see where the gas is.” These ...

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.

This has given scientists their best look yet at the Cosmic Microwave Background (CMB) - the leftover radiation from the Big Bang which fills the entire observable universe. What looks like clouds ...

The structure and composition of the observable universe, within the framework of the theory, depend on how microcells proliferated, and how their energies evolved, during inflation. Each macrocell ...

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

If dark energy is weakening, it stands to reason that eventually gravity will become dominant and the universe will begin to contract. In such a scenario, the universe would collapse back into a ...

This is just a small part of the universe—less than 1% of the entire observable universe—but it is our galactic neighborhood. And it is good to know the geography of your neighborhood.

Equivalent to almost two trillion trillion suns, that’s the amount of mass (or its counterpart as energy) that these images show to exist in the entire observable universe, which extends almost ...