Astrophysics

A serendipitously discovered object nearly as massive as the Milky Way appears to be made of primordial gas that has formed almost no stars

Information theory can help us decode signs of biological activity hiding in the atmospheres of distant exoplanets

Astronomy is beautiful and elegant. The language we use to describe its processes is anything but

Middle-aged stars hit cruise control, stifling their magnetic fields and resisting the slowdown that scientists expected

A newly spotted world is just perplexingly dense

A newly released image from the James Webb Space Telescope provides a detailed view of a star’s infancy

For six seconds tonight, the constellation Orion will appear to lose the vibrant red star at its shoulder—and scientists are thrilled

Amaterasu—the most powerful cosmic ray seen in three decades—seems to come from an empty point of the sky. New telescopes may solve the mystery of its origins

Scientists still can’t explain what is causing unusually bright explosions in space—but a surprising observation might offer clues

Two orbiting stars are causing unsustainably large tides as they draw closer together

Several unexplained measurements are threatening to upend scientists’ understanding of the universe’s origin and fate

Strange patterns in the orbits of small objects in the outer solar system could be explained by gaps in our understanding of gravity rather than an as-yet-unseen new world