SUNSET: 
Astronomers Find Confounding Cone Shape in Cluster Collision
Galaxy clusters take eons to collide. Now, astronomers have caught a pair of merging clusters in an in-between stage never seen before.
What's Next After the International Space Station?
NASA will end support for the International Space Station by 2030, transitioning low-Earth orbit to commercial operations.
How Our Largest Dwarf Galaxy Keeps the Others In Line
New research may explain why satellite galaxies align themselves around the Milky Way
See Comet Leonard at its Best
The year's brightest comet is now on display in the predawn sky this week and next. Here's how to find it.
This Week's Sky at a Glance, December 3 – 11
The crescent Moon at dusk hangs under Venus, then Saturn, then Jupiter. Comet Leonard is at its best before dawn. And welcome in, Orion!
Nearest Supermassive Black Hole Pair Discovered
Astronomers have observed a pair of supermassive black holes set to collide in 250 million years.
December: Geminid Meteors & Comet Leonard
December’s solstice brings the longest northern nights, and it’s a busy month for stargazers: the Geminid meteors, a visit from Comet Leonard, and a plethora of bright stars and constellations.
Meet Proxima Centauri: The Closest Star
Proxima Centauri is the dimmest and smallest of the Alpha Centauri system, but it has the honor of being the nearest star.
Astronomers Watch Black Hole Jet Launch
Astronomers have watched a jet launch from a stellar-mass black hole, shedding light on how these structures form.
This Week's Sky at a Glance, November 25 – December 4
While the Jupiter-Saturn-Venus line keeps shrinking, all kinds of deep-sky sights, naked-eye to telescopic, show themselves on these moonless evenings.
NASA’s DART Mission Launches for Head-on Collision with an Asteroid
The first-ever planetary defense mission is now on its way to the asteroid Didymos and its moon, Dimorphos.
Deep-sky Fishing in Cetus, the Whale
Small telescopes can reel in some big ones in the constellation Cetus, the Whale.
Solar Orbiter to Fly Past Earth Thanksgiving Weekend
The Solar Orbiter mission will fly past Earth Friday night, setting up a dramatic sunward plunge.
Can This Near-Earth Asteroid Help Us Understand the First Interstellar Visitor?
Astronomers have observed an object like ‘Oumuamua — but unlike the first known interstellar visitor, this one is in the solar system.
This Week's Sky at a Glance, November 19 – 27
Orion now rises in the east around 8 p.m. Will Betelgeuse or Rigel be the first of his bright stars to come up? That depends on your latitude; Los Angeles and Atlanta are balance points. The Pleiades and Aldebaran watch this scene from high above.
Did Astronomers Spot a Black Hole in Another Galaxy? Maybe Not
Astronomers might have spotted a stellar-mass black hole in another galaxy — but not everyone agrees with what they found.
A Near-Miss Total Lunar Eclipse
A near-total lunar eclipse will be widely visible across North America on the night of November 18–19. Dress warmly and go for it!
Russia Conducts Antisatellite Test; Space Station Crew Takes Cover
A Russian missile struck a defunct satellite early Monday morning, forcing International Space Station crew to shelter in place.
Has a Stray Piece of the Moon Become a Quasi-satellite of Earth?
A quasi-satellite of Earth, named Kamoʻoalewa, might actually be a chip off our Moon.
Did a Comet Explode Over South America 12,000 Years Ago?
Huge chunks and twisted slabs of dark glass are strewn across a patch of the Chilean Atacama Desert. Do they have a cosmic origin?
