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Is the universe flat and infinite, or something more complex? We can’t say for sure, but a new search strategy is mapping out the subtle signals that could reveal if the universe has a shape.

To catch even a whiff of the universe’s earliest epochs — an age of darkness, and one of new light — Cynthia Chiang builds her own equipment. Then she deploys it at the ends of the Earth.

Cosmologists are using secondary signatures from the cosmic microwave background to map the universe’s hidden matter.

Physicists are translating commonsense principles into strict mathematical constraints on how our universe must have behaved at the beginning of time.

The recent discovery of some of the first galaxies in the universe illuminates the darkest era in cosmic history.

A photograph of the infant cosmos reveals the precise amounts of dark matter and dark energy in the universe, leaving precious little room for argument.

Most every cosmologist believes the universe is flat. A new analysis argues that it’s closed.

Astronomers have known where the universe’s missing matter has been hiding for the past 20 years. So why did it take so long to find it?

For decades, astronomers weren’t able to find all of the atomic matter in the universe. A series of recent papers has revealed where it’s been hiding.