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 ...

A paper published in 2024 theorizes that time may have existed before the Big Bang, but we're still not entirely sure.

For decades, scientists have been puzzled by the missing mass in the universe. While we know that about 85% of the universe is made up of dark matter, the remaining 15% is made up of normal (baryonic) ...

Since the James Webb Space Telescope (JWST) began science operations, astronomers have observed galaxies that existed more ...

A new analysis of astronomical data suggests unknown physics is at work assisting dark energy in acting almost as ...

In recent years, one of the most troubling puzzles in astrophysics has grown more urgent. Scientists have realized that the ...

One of the Holy Grails in cosmology is a look back at the earliest epochs of cosmic history. Unfortunately, the universe's first few hundred thousand years are shrouded in an impenetrable fog.

For decades, astronomers have known something didn’t add up in our universe. The amount of “normal” matter—stars, gas, and ...

The tension comes from two types of measurements. One approach looks far back in time, using the cosmic microwave background—the faint light left over from the Big Bang. The other relies on ...