#skyglow

— By Janet Loehrke | USA Today | May 6, 2026

This image, which was released on April 8, 2026, depicts a nighttime view of Earth that was captured by satellite photography collected daily over the preceding ten years. Michala Garrison/NASA Earth Observatory

Our night sky is getting brighter and brighter — not because of the moon, but due to artificial lighting.

While outdoor lighting is a necessary part of modern society, its widespread use has reshaped natural darkness, affected human and animal health and made the night sky harder to see.

According to a new study that analyzed a combination of satellite images, artificial nighttime lights have brightened Earth by 16% between 2014 and 2022. Researchers from University of Connecticut found that nights are gradually becoming brighter worldwide, though trends vary by region, particularly in areas affected by war or natural disasters. The findings were published in Nature.

In 2022, the United States had by far the highest total luminosity of any country, followed by China, India, Canada and Brazil.

NASA's Scientific Visualization Studio

"For decades, we've held a simplified view that the Earth at night is just getting steadily brighter as human population and economies grow," said senior author of the study Zhe Zhu, director of the University of Connecticut's Global Environmental Remote Sensing Laboratory. "The planet's lighting footprint is constantly expanding, contracting and shifting," Zhu said.

The Glow: Earth's Light Pollution

In the United States, nearly 80% of people reside in urban areas. In many locations, the brightness of artificial light sources obscures the beauty of the night sky. Due to city lights, only the brightest stars, planets and other celestial objects are visible, according to DarkSky International, a nonprofit organization dedicated to protecting night skies.

In the Nature study, researchers also identified areas where artificial light levels had decreased. This dimming was attributed to the Russia–Ukraine conflict in 2022, which triggered a regional energy crisis and caused European nights to darken dramatically.

Built from a decade of daily NASA satellite imagery, the image below compares 2012 with 2023 and highlights shifts in human nighttime activity.

Getting Brighter At Night: Changes in night lights between 2012 and 2023:

Source: NASA's Scientific Visualization Studio

What Is Light Pollution?

Excessive artificial lighting outside is known as light pollution and according to DarkSky, there are four ways that light pollution can happen:

Glare: The intense, uncomfortable light that shines directly at the viewer and obstructs their eyesight.

Skyglow: The brightening of the night sky due to light distributed in the atmosphere by human-caused lighting.

Light Trespass: Unwanted artificial light spilling onto another person's property or space, such as light from a streetlight shining in a bedroom window.

Clutter: Intensely bright lights, which cause visual discomfort. Common examples include extremely bright streetlights or poorly aimed spotlights.

How Much Light Pollution Is In Your Area?

Excessive lighting is a common feature of cities, suburbs and urban towns. These light sources include parking lots, streetlights, advertisements and both internal and outdoor lighting.

The brightness of the night sky can be measured by using the Bortle scale. The scale has nine levels, with Class 9 representing the highest level of light pollution.

The 9 Levels of The Bortle Scale: Artificial light can be measured by ranking its brightness.

Source: SkyGlow Project; Photos: Tevor Hughes, USA Today; Graphic: Janet Loehrke/USA Today

To easily check for artificial light pollution in where you live, visiting the Light Pollution Map to gauge the amount of light is near you.

How Too Much Light Can Impact Wildlife And Humans

Both animals and humans are affected by artificial light.

In animals, research shows that light pollution disrupts a wide range of behaviors, including migration patterns, sleep–wake cycles and habitat development. Species that rely on natural light cues are particularly vulnerable.

According to DarkSky International, sea turtles and birds use moonlight to navigate during migration. Artificial lighting can disorient them, causing them to stray from their routes and often leading to death.

Artificial lights also attract large numbers of insects, which are a primary food source for birds and other animals. Many of these insects are quickly killed when they come into contact with light sources, reducing available food and further disrupting ecosystems.

Source: American Bird Conservancy, Yale University, ScienceDirect; Graphic: Janet Loehrke, USA Today

For humans, artificial light at night can disrupt the body’s natural circadian rhythm by suppressing melatonin, a hormone that helps regulate sleep; this disruption may in turn interfere with biological processes such as hormone regulation, cell growth and DNA repair that help protect against cancer.

In a 2024 peer reviewed study published in ScienceDirect, researchers found that higher exposure to outdoor artificial light at night (ALAN) was associated with a modestly higher risk of breast cancer.

Save Energy: Things You Can Do To Help Lessen Light Pollution

The good part of light pollution is that it is entirely reversible. Anyone is capable of making a difference by using these easy light-dimming tips:

Source: DarkSky International, National Park Service; Graphic: Janet Loehrke, USA Today

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No, These Rainbow Clouds Over Indonesia Are Not Artificial Intelligence (AI)

This colorful cloud over Jonggol, Indonesia, is not a portal to the land of Oz. Or the rainbow road into Asgard from Norse mythology. Or even an AI-generated image. They are iridescent clouds, a rare type of cloud that appear when raindrops interact with sunlight.

According to WABC meteorologist Lee Goldberg, the small water droplets or ice crystals inside of the cloud scatter sunlight, diffracting the light into a spectrum of colors. The rainbow effect is most visible when the sun is partially blocked by something like a mountain or thicker clouds.

“These vibrant displays usually appear near the sun and can last for only a few moments—making them a truly magical sight for anyone lucky enough to catch them,” Goldberg writes.

Ida Pramuwardani, Acting Director of Public Meteorology at the Indonesian climate agency BKMG, told Detik News that the cloud in the video taken over the city southeast of Jakarta is a towering cumulus cloud blocking part of the rainbow.

“At the same time, there are towering cumulus clouds that can cover part of the rainbow, so that the shape looks incomplete or looks like a ‘rainbow cloud’,” Pramuwardani said in a translated interview.

These clouds are also not a direct sign that a storm is coming in. Instead, rainbow clouds indicate that convective clouds are growing and that there is the possibility that rain will start to fall soon.

Understandably, the beautiful sight reportedly stopped traffic, as onlookers rushed to capture footage of these candy colored clouds.

— Laura Baisas | Tuesday May 5, 2026

by Xiaohan Wang

vampire | \ ˈvam-ˌpī(-ə)r \

Video introduces one of my favorite short filmmakers -  Harun Mehmedinovic, of the Skyglow Project. Original caption: