Scientists once thought luminiferous ether pervaded the cosmos. Michelson and Morley’s ingenious experiment to find it produced one of the most famous null results in astronomy.

The strange lunar swirl Reiner Gamma marks a starting point to explore several craters visible near the lunar terminator tonight.

Rising around 7:30 P.M. local daylight time, Saturn reaches an altitude above 40° in the southeast by local midnight. Visible ...

Discover how star clusters influence galaxy evolution and planet formation, revealed by JWST in a groundbreaking study.

The Sun passes the celestial equator moving south today, marking the Northern Hemisphere’s transition to autumn.

Air Force Secretary Troy Meink's announcement is the first official U.S. acknowledgment of space-based weapons.

Our current planet-hunting techniques are unable to detect an Earth-like planet in an Earth-like orbit around a Sun-like star.

A possible Jupiter-sized object circling the brown dwarf CD-35 2722 b has implications for planetary science, including what counts as a moon beyond our own solar system.

Here's what's launching Sept. 21–27: two Chinese rockets go up, Rocket Lab delivers an Earth-observation satellite, and SpaceX closes things out with a national security mission for the U.S. Space ...

Now is the best time to catch 145-mile-wide 3 Juno as it passes through a random collection of 9th- and 10th-magnitude stars.

Dark-sky sights take center stage as Saturn's moons dance and Venus mingles with the Moon in the sky this week.

Dione crosses Saturn’s north pole, projecting its shadow onto the cloud tops as Tethys disappears into the planet’s shadow.