SUNSET: 
Astronomers Find 100,000-light-year Bow Shock in the Milky Way’s Outskirts
New simulations showed astronomers where to look for evidence of a dwarf galaxy's bow shock as it crashes through the Milky Way's halo.
As an Asteroid-Hunting Mission Approaches Its End, What's Next?
The pioneering NEOWISE observatory celebrates a milestone, even as the end of the mission draws near.
Watch Jupiter's Moons in Unusual Lineups
You'll have five opportunities in the coming months to see Jupiter's moons in interesting alignments.
This Week's Sky at a Glance, December 15 – 24
The waxing Moon passes Saturn, jumps over Jupiter, then jumps the Pleiades. Sirius and Procyon rise earlier, but the Summer Triangle still hangs on.
Vesta Sets Sail Across Orion
Look who's visiting this winter in Orion: Vesta, a bright asteroid with a dark side.
Get Ready to Greet the Geminid Meteor Shower!
The year's most spectacular meteor shower is upon us. Prepare to enjoy the Geminids under a dark, moonless sky, when you might see more than 100 meteors per hour.
Cassiopeia A: A Festive Supernova Remnant
New near-infrared observations from the Webb telescope reveal intricate strands of debris from the exploded star.
Buried Polygons on Mars Point to “Stark Environmental Transition”
Polygons buried beneath the surface of Mars indicate an abrupt transition in the planet's early history.
Asteroid to Cover Betelgeuse on Night of December 11-12 (Updated: Livestream Link)
Astronomers are gearing up for an unusual celestial event: an asteroid’s occultation of an iconic star.
This Week's Sky at a Glance, December 8 – 17
The best meteor shower of the year peaks late Wednesday night. And if you're not positioned to see the tiny asteroid occult Betelgeuse Monday evening, watch by livestream!
Dark Halos and Warped Disks
Galaxies are embedded within halos of dark matter, and the tilt of those halos can affect the galaxy's stellar halo and stellar disk.
The Comet-Asteroid Chiron Has Rings — And They're Changing
A series of stellar occultations has provided evidence that the ring system around this strange object is evolving drastically.
Astronomers Discover 562 New Candidate Strong Lenses With Machine Learning
An international research collaboration trained computers to sift through millions of images for cosmic treasure.
This Week's Sky at a Glance, December 1 – 9
These moonless evenings open up the deep sky. For many of us the viewing is especially crisp through the low-humidity December air. The Big Dipper lies low, Cassiopeia stands high, and the Andromeda Galaxy crosses the zenith.
December Podcast: A Tower of Brilliant Stars
This month’s Sky Tour podcast introduces you to a “tower of brilliance” in the eastern evening sky, along with tips for finding four planets and watching mid-December’s impressive Geminid meteor shower.
Six Sub-Neptunes Discovered 100 Light-Years Away
Astronomers have uncovered six sub-Neptune exoplanets dancing in lock-step around the same distant star, shedding light on their formation.
Do Glaciers on Mercury Suggest Such a Planet Could Be Habitable?
Salt glaciers on Mercury suggest conditions friendly to life — but not life itself — might once have existed on the innermost planet.
Amateur Astronomers Discover an Asteroid’s Moon
The small object orbiting around main-belt asteroid 5457 Queen’s is the second confirmed asteroid moon discovered during a stellar occultation.
This Week's Sky at a Glance, November 24 – December 3
This Tuesday the 28th we will see the Moon rise in twilight as far north as it possibly can. Do you know why?
Asteroid Named for Sky & Telescope’s Gary Seronik
The International Astronomical Union has named the asteroid provisionally designated as 1993 FE15 after Sky & Telescope's Consulting Editor Gary Seronik: 20046 Seronik.
