After five years of staring at the night sky from a mountaintop in Arizona, the most ambitious galaxy-mapping experiment ever ...

The most precise measurement yet shows the Universe is expanding faster than expected, deepening the Hubble tension. The ...

Today scientists rely on two methods. The first is late-universe observation (or observation of the universe as we see it ...

Citizen science project uses Euclid telescope data to find gravitational lenses. Public helps identify light-bending galaxies ...

Space, as we all know, is big. In fact, it’s more than big; it’s vastly, hugely, mind-bogglingly big. But how big is that, exactly, and how do we go about assigning actual, quantifiable distances ...

By studying galaxy clusters separated by hundreds of millions of light-years, Penn physicist Patricio Gallardo and ...

Get a first look at the completed observatory.

The end of the universe has always felt like a distant abstraction. But new calculations suggest that our original timeline might have been wildly optimistic. According to a team of Dutch scientists, ...

Two billion years after the cosmos banged into existence, a mysterious force known as dark energy began shoving space outward ...