SUNSET: 
Wildfire Threatens Kitt Peak National Observatory
The Contreras wildfire has been threatening the historic Kitt Peak National Observatory in southern Arizona.
What we know about Light Pollution – and What We Don’t
The International Dark-Sky Association’s has summarized more than 300 peer-reviewed studies on the effects of artificial light at night in an effort to help dark-sky advocates.
Solar System Gets its Ducks in a Row
We'll have not one but many opportunities to enjoy a rare lineup of the bright planets over the next few weeks. Amazingly, they'll be aligned in order of their distance from the Sun.
This Week's Sky at a Glance, June 17 – 25
The five naked-eye planets form a diagonal line in the dawn this week — in order of their distance from the Sun, no less. And the waning Moon visits each one in turn, day by day.
A Strange White Dwarf with a Chaotic Past
New observations show that both rocky and icy worlds fell onto a white dwarf, indicating past orbital chaos in the system.
Life and Death in Nearby Galaxies
New images of nearby galaxies and their surroundings reveal details in galactic formation and evolution — and puzzles that remain to be solved.
Have We Found the First Rogue Black Hole in the Milky Way?
Hubble observations have revealed a stellar-mass compact object — a black hole or possibly a neutron star — wandering our galaxy.
The Gaia Revolution: New Data and Strange Stars
Astronomers will use the newest data release from the Gaia mission to explore stellar tsunamis, Milky Way history, and more.
Newest Starlink Satellites Have Gotten Brighter Again
Changes to the design of Starlink satellite spacecraft have made them brighter again, though still dimmer than the original design.
This Week's Sky at a Glance, June 10 – 18
The waxing gibbous Moon shines with Spica, then occults Delta Scorpii. Meanwhile, all seven planets other than Earth are forming into a diagonal line across the east to southeast at dawn.
Perseverance Watches Wild Winds on Mars
NASA’s Perseverance rover is recording the windy weather in Jezero Crater, chronicling its role in making the Red Planet dusty.
An Unusual Source Deepens Fast Radio Burst Mysteries
A new source of fast radio bursts raises questions about how much we really know about these mysterious flares.
Tau Herculid Meteors Surprise and Delight
We touch on the highlights of the memorable Tau Herculid meteor shower and also report on the recent outburst of the recurrent nova U Scorpii.
This Week's Sky at a Glance, June 3 – 11
For three nights running, the waxing Moon will pose equidistant from the two brightest stars of Leo. The Cassiopeia W lies exactly level in the north. And for that to happen, Kochab has to be straight above Polaris.
The Life and Times of Immortal Stars
Under the right conditions, stars could become immortal. How is this possible, and what does it mean for these stars’ surroundings?
June: Pre-dawn Planet-Palooza
Download this month's Sky Tour podcast to find out where and when to spot a rare alignment of five planets in the sky before dawn.
Meet Denebola, and Catch a Lion by the Tail
Meet Denebola, the tail of Leo, the Lion. This young star is a fast rotater but otherwise not that different from our Sun.
This Week's Sky at a Glance, May 27 – June 4
The crescent Moon passes Pollux and Castor in the western twilight. Jupiter aligns with Mars in the dawn, then they edge apart. And a strong new meteor shower will either happen or it won't!
Update on a Possible Outburst of Meteors
Will there be a new meteor shower on the night of May 30–31? There's only one way to find out.
Mystery of the Sun's Chemical Makeup Lingers
Astronomers think they might have a solution to the conundrum of the Sun's chemical composition.
