Astronomy

The new finding is challenging established theories of how planets come to be.

If and when physicists are able to pin down the metal content of the sun, that number could upend much of what we thought we knew about the evolution and life span of stars.

Astronomers suspect that there’s a large planet hiding out in the distant fringes of the solar system. At a recent workshop, they brainstormed ways to coax it into view.

Astronomers have found stars dating from a long-ago collision between the Milky Way and another galaxy. The crash helps to explain why the Milky Way looks the way it does.

Computer simulations have become so accurate that cosmologists can now use them to study dark matter, supermassive black holes and other mysteries of the real evolving cosmos.

A living, breathing garden in Seattle serves as the perfect backdrop to an astrobiologist’s search for life on faraway planets.

Detailed images of disks swirling around young stars show the details of how solar systems come to be.

A roundup of some of the most important discoveries gleaned so far from the Gaia space observatory’s new map of the galaxy.

Two ways of measuring the universe’s expansion rate yield two conflicting answers. Many point to the possibility of new physics at work, but a new analysis argues that unseen errors could be to blame.