SUNSET: 
Is the Day 12 Hours Long on the Equinox? It's Complicated
The Earth's atmosphere and the large size of the solar disk result in unequal days and nights, even on the equinox.
To Catch Beads of Sunlight, Here's Where You Should Head for October 14th's Annular Eclipse
Some eclipse-chasers will choose to view a “broken ring” and a long display of Baily's beads on October 14, 2023.
See the Winning Images of Royal Observatory Greenwich's Astrophotographer of the Year Contest
See the images that won the Royal Observatory Greenwich's Astronomy Photographer of the Year award.
NASA Finds No Evidence UFOs Are Extraterrestrial, Promises Further Study
An independent study shows how NASA can help understand unidentified anomalous phenomena, more colloquially known as UFOs.
This Week's Sky at a Glance, September 15 – 24
Comet Nishimura shines at its brightest... but don't be disappointed, we warned you. Meanwhile Jupiter outdoes Saturn as an evening light, and the Little Dipper dumps water into the Big Dipper.
Galaxies Outline Bubble 1 Billion Light-Years Wide in Space
A newfound cosmic alignment of galaxies challenges fundamental ideas about the nature of our universe.
Dark Matter Clumps Float Between Galaxies, Data Shows
Astronomers have found clumps of dark matter 30,000 light-years wide in the space between galaxies in the distant universe.
Peculiar Pulsar Throws “Cosmic Cannonballs”
Astronomers think a city-size star that’s spinning faster than a kitchen blender is shooting out plasma torpedoes.
This Week's Sky at a Glance, September 8 – 17
Comet Nishimura teases us shyly low on the dawn horizon, then low on the dusk horizon. The Milky Way arches high across the evening sky, and Saturn invites your telescope.
X-ray, Moon Missions Launch from Japan
In an ambitious mission pairing, Japan launched a next-generation X-ray observatory and an innovative lunar lander.
Action-packed Sky: Saturn, Comet Nishimura, and More
September is Saturn's time to shine. We also check on Comet Nishimura — now at 5th magnitude and still brightening — and look forward to a dramatic asteroid occultation. Not to mention that Jupiter just took another hit.
September Podcast: Explore the Summer Triangle
Daylight hours are getting shorter in the Northern Hemisphere, which means the hours for stargazing are getting longer throughout September! So stream or download this month’s Sky Tour astronomy podcast for lots of great tips on what you can see this month in the evening sky.
Astronomy in Space with David Dickinson
India Launches Aditya L1 Solar Observatory
India’s first dedicated solar science mission Aditya L1 heads spaceward.
This Week's Sky at a Glance, September 1 – 10
Vega culminates at the zenith around the end of twilight. Arcturus and the Dipper sink through the evening. Saturn and Jupiter rule the late-night hours, and Venus shines at dawn.
El Niño and the 2024 Total Solar Eclipse
What will the ongoing El Niño event do to the chance of cloud cover along the 2024 total solar eclipse track?
The Moon Is "Blue" This Wednesday...Or Is It?
If skies are clear this Wednesday, you'll see the full Moon — but it's not the "true" Blue Moon.
Rubble-Pile Asteroid Bennu Has Layers
The asteroid Bennu is a so-called rubble pile, but new results from NASA's OSIRIS-Rex mission indicate this heap of rubble has layers.
Fast Radio Burst Roundup
They’re powerful, they’re fast, and we aren’t sure about what causes them, but astronomers are closer than ever to understanding the source of mysterious fast radio bursts.
This Week's Sky at a Glance, August 25 – September 3
Saturn comes to opposition. Vega crests at the zenith, while Arcturus declines in the west. Venus shines at dawn. Go out before dawn's very first light, and you get an Orion-starring preview of the evening sky at New Year's.
Solar Cycle May Trigger Clouds on Neptune
Nearly 30 years of observations indicate that Neptune’s clouds and brightness vary with the Sun’s activity.
