The solar system's "ice giants" display surprisingly energetic weather patterns — and a new analysis suggests they're all confined to a very thin outer layer on each planet.

NASA's revolutionary planet-hunting spacecraft suffered malfunction this week that leaves it unable to point precisely at its target stars.

Harvard College Observatory is digitizing its famed collection of more than 500,000 glass sky-survey plates and has just released the first data set.

Astronomers have been waiting for our galaxy’s slumbering supermassive black hole to stir for a snack. Instead, the universe handed them a different treat.

New analysis of Apollo samples shows that water trapped in eruptions from the Moon's interior have the same isotopic fingerprint as terrestrial water — a key confirmation that the Moon formed after something big hit Earth.

Seven clouds of hydrogen dotting the space between two iconic galaxies might be crumbs from a past encounter or evidence for the elusive cosmic web theorized to fuel galaxy growth.

Sky & Telescope introduces our new eBook library, where you can download digital books about your favorite topics free with registration.

An exceptionally powerful gamma-ray burst on April 27th wowed astronomers around the world — and its fading was tracked by an alert backyard observer.

It's been nearly 19 years since fragments of Comet Shoemaker-Levy 9 slammed into Jupiter. Recent observations show that water delivered by the comet still lingers in the planet's stratosphere.

Just as it's coming closest to Earth, the big ringed planet is in the news in multiple ways — including the discovery of a long-lasting hurricane at its north pole.

There's a big gap in the dusty disk around the young star V1247 Orionis. Such a gap should be carved out by one or more planets, but astronomers can't find any.

After nearly four years of successful observing, the largest infrared space telescope ever launched has run out of cryogenic coolant, permanently ending its science operations.

A massive neutron star and its lightweight sidekick provide a unique space laboratory to test general relativity. So far, gravity keeps behaving as it's supposed to.

A group of 90 people from around the U.S. and the world joined S&T in early April for an aurora adventure in Iceland.