Cosmology

Just how big can a star become? The answer depends on when in cosmic history you’re asking the question

This enormous chain of hundreds of galaxies—a cosmic filament—is twisting through space 400 million light-years away

Physicists cannot access anything that existed before the start of time and space, but they have theories

You might think galaxies can’t ever find each other in our runaway cosmos, but it turns out gravity can sometimes overcome even the stretching of space itself

Dating to only a billion years after the big bang, JADES-ID1 may be the earliest, most distant galaxy protocluster astronomers have ever seen

The puzzle of time remains one of the most persistent obstacles to a unified theory of physics

The six-year results from the Dark Energy Survey highlight unresolved tensions in standard cosmological theory

Scientists have found the best evidence yet for long-predicted “failed galaxies”

Record-breaking objects can tell us about the most powerful events in the cosmos—sometimes

In our topsy-turvy universe, sometimes the farther away an object is, the bigger it seems to be

Theorists have found that a “warm” version of cosmic inflation is consistent with known physics, linking it to the hunt for dark matter

A controversial prediction about black holes and the expansion force of the universe could explain a cosmology mystery