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For practically all of natural history, the night sky was pristine.
This expansive photograph showcases the Milky Way, the two Magellanic Clouds, and several other impressive celestial features at the Cerro Tololo Inter-American Observatory. Although it’s located at an impressive 2200 meters (7200 feet) above sea level, many other mountains within the Andes mountain range have even higher altitude summits.
Credit: Samara Nagle/NRAO
Post-sunset, only the Moon, stars, planets, and Milky Way illuminated the heavens.
Under a pristine night sky, the Milky Way’s center casts shadows. As light pollution worsens, nebulosity and stars disappear, until maybe a few dozen stars remain. The numbers 1 through 9 are the Bortle scale, which provides observers with a metric to measure the darkness and clarity of the sky overhead at their location. Only a few locations remain on Earth with pristine, dark skies.
Credit: ESO/P. Horálek; M. Wallner
However, the dawn of electrification has resulted in a huge loss of darkness.
This map of the world depicts light pollution as a function of geographic location. Every location with a yellow-or-brighter coloring has more brightness coming from the ground than the natural sky, highlighting the severity of light pollution across the world, particularly in Europe, Asia, and the Americas.
Credit: Falchi et al., Science Advances, including Dan Duriscoe/NPS; Bob Meadows/NPS; Jakob Grothe/NPS contractor, and Matthew Price/CIRES and CU-Boulder
Additionally, satellite megaconstellations create thousands of interference-rich bright streaks.
This image, taken on August 10, 2022, shows the results of a stacked set of images of the same region of sky, the nebula Sharpless 150 (SH2-150), taken over a single night. The streaks result from satellites passing through this one field-of-view over the course of one night alone.
Credit: Fegato/Cloudy Nights
Efficient, low-pollution lighting plans can mitigate those losses, but haven’t been widely adopted.
The greater the amount of light that gets shunted upward or horizontally, the more light pollution will be emitted by a fixture. The best light fixtures will shunt all their light downward, toward the ground, as shown at right. However, the most common types of fixtures are the ones closer to the left of the diagram.
Credit: Dwayne Kula/LED Lighting Supply
To raise awareness, DarkSky International created a photo contest: Capture the Dark.
This animation changes between two 30-second exposure images taken with the same camera from a protected dark-sky site (at the summit of La Palma, dark) and from a typical modern rural sky (in Washington State near Mt. St. Helens, blue). The difference between the two images, as well as the difference in total sky brightness, is profound.
Credit: E. Siegel, 2025
Over 2200 entrants competed in 2025’s competition.
One of the special categories in the 2025 DarkSky International photo contest was the “Visit Tucson Location Award,” where this photo won 1st place. The starry sky is opposed by terrestrial green lights: those emitted by the southwest synchronous firefly, photographed here in Tumacácori.
Credit: Celeste Boudreaux
Winners from across eight categories, plus three special awards, are highlighted here.
High School student Michael Telesco captured this outstanding view of the Dolphin Head nebula, also known as Sharpless 2-308, showcases a bubble-like ionized feature surrounding the bright Wolf-Rayet star EZ Canis Majoris. This photo was awarded 3rd place in the Young Astrophotographers category, showcasing what can be captured even from the relatively high light polluted region of the Florida Keys.
Credit: Michael Telesco
JJ Rao‘s red sprites won 1st place in the Capture the Dark category.
The large sprites captured here are phantasmal when glimpsed with human eyes, as they persist for only a hundredth of a second. Because they are so brief, they require extremely dark skies to be captured. This was the 1st place winner in the “Capture the Dark” category, arguably the most competitive category in the 2025 DarkSky International photo contest.
Credit: JJ Rao
Mónica Mesa‘s aurorae took second.
One of several award-winning photos involving aurorae in this year’s contest, this photograph, titled “Whispers of the Dancing Auroras,” was taken in Iceland and won 2nd place in the “Capture the Dark” category. The sky and the foreground were captured with different length exposures and different camera settings.
Credit: Mónica Mesa
Panoramas dominated the International Dark Sky Places category.
This panorama, taken at the entrance to the Aoraki Mackenzie International Dark Sky Reserve in New Zealand, showcases one of the most significant dark sky reserves on Earth. The bright, blue stars found near the galactic plane shine brilliantly overhead, while the red regions represent ionized hydrogen’s natural red-colored emissions as the electrons recombine with their atomic nuclei. This submission won 1st place in the International Dark Sky Places category.
Credit: Tom Rae
Horizon glows reveal light pollution, even here.
This glorious 360-degree panorama showcases the “towards the galactic center” and the “away from the galactic center” directions simultaneously, and won 2nd place in the “International Dark Sky Places” category. Note the bright glow near the horizon: evidence of light pollution, even in the relatively pristine location of Death Valley, California.
Credit: Dan Zafra
By not illuminating urban landmarks, city nights shine brighter.
Although it’s known as the City of Light, Paris turns off the lights on landmarks like the Eiffel Tower and Sacré-Cœur, saving energy and reducing light pollution at the same time. This astrophoto won 1st place in the Dark Sky Friendly Lighting and Design category, with this composition known as “Paris, Asleep In The Pre-Dawn Hours.”
Credit: Gwenael Blanck
Few locations are free from light pollution.
This incredible photograph won 1st place in the “The Impact of Light Pollution” category in the 2025 DarkSky International photo contest. Taken in the French Alps by Ambre de l’AIPe, the cloud-covered valley still glows eerily with the light from the town Chamonix, below, polluting the landscape with its luminance.
Credit: Ambre de l’AIPe
In severe instances, only a few visible stars appear.
Called “Traces of the Stars,” this 2nd-place-winning astrophotography submission in the Light Pollution category highlights just how few stars can be seen from the center of a highly light polluted area, such as Shanghai, China. Whereas many thousands of stars can be seen by the naked eye from a true dark sky site, as few as a couple of dozen stars can be spotted from the most heavily light polluted areas on Earth.
Credit: Xin Wang
Additionally, satellite interference of star fields is ubiquitous.
Astrophotographer Shi Pu captured this 3rd-place-winning image of Messier 101 (the Pinwheel galaxy) against its background star field, only to find a large number of satellite streaks, some brighter than others, polluting his image. Since the rise of satellite megaconstellations in 2019, this new type of space pollution has interfered with night sky observations across the electromagnetic spectrum for professional and amateur astronomers alike.
Credit: Shi Pu
There was a remarkable “Creatures of the Night” category.
This fluorescent scorpion, photographed in the desert of Mexico, is the focus of this image, while the constellation of Scorpius shines, blurry, in the background. This image was the 1st place awardee in the category of “Creatures of the Night” in DarkSky International’s 2025 photo contest.
Credit: Oscar Leonardo Chavez Torres
“Young Astrophotographers” got its own category as well.
Teenage astrophotographer Oldřich Špůrek captured this photo of a panoramic Milky Way over Jizerka, the highest-altitude village in the Czech Republic. Titled Gems of Jizerka, this is the 1st place-winning submission in the Young Astrophotographers category for 2025’s DarkSky International photo contest.
Credit: Oldřich Špůrek
Mobile photography shone bright for aurorae,
During a trip to Iceland, mobile astrophotographer Sadeq Hayati captured this 1st-place-winning photo of a multicolored, dancing aurora with a large rock formation (and a human beneath it) silhouetted in front of the night sky.
Credit: Sadeq Hayati
and for capturing luminance from solar winds.
This submission from Katrina Brown won 3rd place in the Mobile Astrophotography category, showcasing the salt flats (below) and the colors that the solar wind induce in the atmosphere (above, and in reflection, below) here on Earth. One sixteen second exposure was all it took to capture this iconic sight.
Credit: Katrina Brown
“Deep Sky Observations” highlighted my three personal favorites.
This mosaic of the Vela Supernova Remnant reveals a complex, layered structure from the primary emission signals of the nebula itself. Astrophotographer Alpha Zhang took a whopping 1310 frames totaling ~109 hours of exposure time to create this mosaic, the 1st place winner in the Deep Sky Observations category of 2025’s DarkSky International photo contest.
Credit: Alpha Zhang
Winning 2nd place in the Deep Sky Observations category under the submission Furnace of Life, this view of the Rosette Nebula, a young star cluster inside a star-forming region, highlights the ionized features of hydrogen, oxygen, and sulfur gases. All told, 225 separate frames of 10 minutes each were used in the creation of this image.
Credit: Rod Prazeres
Leveraging a whopping 27 hours and 15 minutes of exposure time across 327 separate frames, this stacked view of the Horsehead Nebula in the constellation of Orion showcases several bright, young stars, the extended emission of hydrogen atoms, and the brilliant reflection feature of the Flame Nebula all alongside one another.
Credit: Tiffany Effinger
This photo of Comet C/2023 A3 and the Milky Way showcases two features that were invisible to young astrophotographer Siddharth Patel’s eyes from the city where he lived, so he and his family drove to Fingal, Ontario, where skies are darker. There, he acquired this image, which won the 1st place in the special People’s Choice Award category.
Credit: Siddharth Patel
Mostly Mute Monday tells an astronomical story in images, visuals, and no more than 200 words.
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Travel the universe with Dr. Ethan Siegel as he answers the biggest questions of all.