SUNSET: 
Astronomers Spot Rare Einstein Cross — and a Massive Clump of Dark Matter
The discovery of a rare Einstein Cross — five images of the same galaxy — reveals a trillion-solar-mass dark matter clump.
This Week's Sky at a Glance, September 19 – 28
On these dark evenings the Perseus Double Cluster and the Andromeda Galaxy, M31, await in the northeast. They're only two fist-widths apart.
Environmental Exclusions Proposed for U.S. Satellite Industry
In a move that’s concerning astronomers and environmental groups alike, the Federal Communications Commission (FCC) has proposed reducing environmental oversight of space-based operations.
Early Galaxy Hosts Black Hole with the Mass of 50 Million Suns
Astronomers using the James Webb Space Telescope have confirmed that, just 800 million years after the Big Bang, there is a galaxy that contains a supermassive black hole — and not much else.
Last Call for a Remarkable Titan Shadow Transit
Titan joins its shadow for a "grand finale" this October.
Did Asteroids Once Rain Down on Earth?
A surge of asteroids might have peppered the inner solar system some 800 million years ago, in a short-lived shower that left its mark — literally — on Earth and its neighbors.
Royal Observatory Greenwich / ZWO Astronomy Photographer of the Year
See the images that won the 2025 Astronomy Photographer of the Year award.
New Comet SWAN (C/2025 R2) Pops Out from Behind the Sun
Ukrainian amateur discovers a bright, new comet now in the evening sky.
Celebrating 10 Years of Gravitational-Wave Discoveries
The LIGO gravitational-wave detector celebrates its 10th birthday with the clearest signal yet from a pair of merging black holes.
This Week's Sky at a Glance, September 12 – 21
Venus has double close conjunctions with the crescent Moon and Regulus in the dawn next Friday the 19th. Meanwhile, Saturn and Neptune are coming to opposition.
Best Evidence Yet for Past Life on Mars?
The Perseverance has found compounds associated with life on Earth. But whether they indicate life on Mars awaits sample return.
Attending This Year's Season of Star Parties
S&T editors attended star parties in the past months in various locations around the country to observe with fellow stargazers.
A New Kind of Satellite Could Damage Your Eyes
Reflect Orbital plans to launch gigantic satellites to reflect sunlight into regions where night has already fallen, potentially harming eyes, altering sleep, and blocking the starry sky.
From the Sun to the Stars, Astronomy in Photos
New observations reveal turbulent flows in the supernova remnant Cassiopeia A and in the solar corona.
Scientists Release the Latest Gravitational-wave Detections
The number of gravitational-wave signals has just doubled with the release of the newest catalog of events.
This Week's Sky at a Glance, September 5 – 14
Saturn nears opposition as the full Moon passes it. Once the Moon goes away, the dark sky offers binocular users the Dumbbell Nebula and the globular M2.
Mars Might Have a Surprisingly Large, Solid Core, Marsquakes Reveal
Marsquakes reveal a lumpy, viscous mantle and a large, solid inner core, with profound implications for Mars past, present, and future.
Webb Telescope Finds Interstellar Comet Has Unexpected Composition
Observations with the James Webb Space Telescope have shown the new interstellar Comet 3I/ATLAS is surprisingly rich in carbon dioxide.
Sweet Prospects for Comet Lemmon (C/2025 A6)
A promising comet could reach naked-eye brightness next month. Here's how to track it.
Meet 2025 PN7, Earth’s New Quasi-moon
Just discovered, it’s been orbiting the Sun alongside Earth for decades, and will continue to do so for decades more
