Astronomers recently discovered that there is not nearly enough ultraviolet light from stars and quasars in the local universe to account for observations of intergalactic gas.
David Levy shares his recollections of that amazing day — July 16, 1994 — when the first fragment of a comet he helped discover slammed into Jupiter.
A cluster of detections in the Northern Hemisphere sky might point to a source for the most energetic particles bombarding Earth's atmosphere.
New Horizons will reach Pluto a year from today, and the scientific community is abuzz with speculation about what the space probe might see when it gets there. Meanwhile, the New Horizons team scours the skies for a Kuiper Belt Object that New Horizons can visit after its Pluto flyby.
How did the the innermost planet get its huge iron core? New computer modeling suggests that Mercury is a lucky survivor of chaotic primordial smashups.
Astronomers have discovered two stars that lie more than 700,000 light-years from Earth, making them the most distant stellar members of our galaxy ever detected. Blogger John Bochanski tells the story of how his team found these faraway stars.
Not every set of closely paired stars requires binoculars or a telescope to "split". Here's a guide to summertime doubles you can tackle with your eyes alone.
Astronomers have discovered a spike of X-ray emission in galaxy clusters — “ordinary” interpretations don’t hold up, so some are turning to dark matter for answers.
A new analysis confirms that an exoplanet thought to orbit in the habitable zone of the star Gliese 581 actually doesn’t exist.
Astronomers have detected a high-speed, long-lasting gas streamer spewing from the active galactic nucleus of NGC 5548. This discovery might provide new insights into how supermassive black holes influence their host galaxies.
Whether you're a seasoned observer or a novice, star parties provide the perfect opportunity to kick back and enjoy the night sky with some fellow astronomy enthusiasts.
On July 5th, the Moon has a remarkably close brush with Mars, followed two nights later by a similar rendezvous with Saturn.
Two bright asteroids now appear extremely close to one another in the evening sky. Here's how to spot them in binoculars or a small telescope.
Astronomers have discovered that one member of a pair of supermassive black holes is actually a pair itself, turning the system into the most distant black hole triplet yet detected and raising hopes for future discoveries.
Comet 67P/Churyumov-Gerasimenko only woke briefly before starting another nap, expected on-again-off-again behavior that bodes well for the comet-chasing spacecraft's arrival in August 2014.
Astronomers now know the secret of this moon's strange two-faced appearance, but it's still remarkable to watch the "now you see it, now you don't" performance as it moves around Saturn.
Sky & Telescope contributing editor Govert Schilling has been selected as the winner of the 2014 David N. Schramm Award.
Saturn’s largest moon Titan played a cameo as an exoplanet, allowing astronomers to better understand how a thick layer of haze or clouds might affect their observations of more distant alien worlds.
Scientists might have discovered the source of the mysterious Cold Spot in the Cosmic Microwave Background: an enormous supervoid.
Fleeting radar features in a sea in Titan’s northern hemisphere are a tantalizing possibility of seasonal changes.
Despite skepticism from scientists and politicians alike, NASA is proceeding with its asteroid redirect mission and has found six candidates for exploration so far.
The top of Cerro Armazones in Chile yielded on June 19th to a blast that paves the way for the European Extremely Large Telescope.
Noctilucent clouds form at the boundary between Earth and space. Their electric blue billows incite the imagination and inspire us to keep watch at dusk for their arrival.
Since Thorne-Żytkow Objects were proposed forty years ago, no one has actually seen one of these exotic stellar hybrids – until now.
The prolific comet hunter William A. Bradfield tallied 18 comets in his lifetime, each discovered visually and credited to him alone.