Astronomy

The final results from the Atacama Cosmology Telescope offer the sharpest, most sensitive view of the early cosmos that anyone has ever seen

Four small, newly discovered worlds are less than six light-years away from Earth, and their discovery reinforces a cautionary tale from planet hunting’s prehistory

In colorful photographs of galaxies, stars, planets, and more, what you see isn’t necessarily what you get

The March 13–14 lunar eclipse will be an all-night affair you won’t want to miss

The question of whether aliens can detect our modern civilization depends on what signs they’re looking for—and, crucially, their distance from us

With radio and infrared telescopes, astronomers can pierce the dusty veil of our galaxy and map its farthest reaches

Asteroid 2024 YR4’s risk of hitting Earth is shifting with new data, astronomers say

“Keep your eye on the ball” is a motto for many athletes—and for astronomers trying to find Earth-threatening space rocks

A newly confirmed exoplanet around a nearby sunlike star might be astronomers’ best chance yet to look for life beyond the solar system—but it’s still no place like home

The possibility of the asteroid 2024 YR4 impacting our planet might not be ruled out until 2028, raising the prospect we’ll need to prepare for the worst

The number of planets that orbit the sun depends on what you mean by “planet,” and that’s not so easy to define

Observatories in Chile’s Atacama Desert, including the world’s largest optical telescope, could be blinded by light pollution and other unwanted side effects from the proposed construction of a renewable energy megaproject