Learn how many stars there are in the Milky Way, and how astronomers count them.

The mass of the entire universe can also be estimated by measuring how the expansion rate has changed since the Big Bang. Normal matter and dark matter have acted to decelerate cosmic expansion, while ...

According to the equations that govern black holes, the larger one of these cosmic behemoths is the lower its average density ...

We know how the universe began. An event we call the Big Bang started it all about 13.8 billion years ago. How the universe ...

How can the behavior of elementary particles and the structure of the entire universe be described using the same mathematical concepts? This question is at the heart of recent work by the ...

According to data from the Hubble and James Webb Space Telescopes, the origins of the free-flying photons in the early cosmic ...

It will be a view unlike any other — completely invisible, exceptionally quiet and utterly transformative. Deep in the first moments of the Big Bang, the entire cosmos shook and rumbled. Those quakes ...

"For the last 20 years, people believed that the cosmological constant is positive, and the universe will expand forever," Tye says. "The new data seem to indicate that the cosmological constant is ...

How will the world end? While some, like Robert Frost, have waxed poetic about the end of life on Earth—fire or ice—others have been looking to science to solve the mystery. Even still, others have ...

Calculating the total mass of the universe is not simple, because most of the mass is invisible. In a pie chart of the contents of the universe, only 5 percent is normal matter, atoms that make up all ...