How satellites could be disrupting your sleep cycle

More than 12,000 satellites are in low-Earth orbit, with space companies planning to launch tens of thousands more that astronomers say could ‘completely change the night sky’ The Independent's journalism is supported by our readers. When you purchase through links on our site, we may earn commission. NewsHealthHow satellites could be disrupting your sleep cycleMore than 12,000 satellites are in low-Earth orbit, with space companies planning to launch tens of thousands more that astronomers say could ‘completely change the night sky’Julia Musto in New York Thursday 05 March 2026 19:37 GMTBookmarkCommentsGo to commentsBookmark popoverRemoved from bookmarksClose popoverFCC Clears Amazon to Expand Satellite FleetYour support helps us to tell the storyRead moreSupport NowFrom reproductive rights to climate change to Big Tech, The Independent is on the ground when the story is developing. 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We believe quality journalism should be available to everyone, paid for by those who can afford it.Your support makes all the difference.Read moreCommunications satellites being launched into space could bring enough light pollution to disrupt the human sleep cycle, scientists and doctors at Northwestern University Feinberg School of Medicine have warned.Exposure to light from the satellites at night could threaten the body’s internal clock, which tells the body when it is time to wake up and fall asleep and affects hormone levels, digestion and body temperature, they said.Even short-term disruptions to this clock - also known as the circadian rhythm - could lead to problems with wound healing, digestive issues, memory loss and a lack of energy, according to the Cleveland Clinic. In the long-term, health conditions can affect the cardiovascular system, nervous system, metabolism, gastrointestinal system and endocrine system.And poor quality sleep has been shown to result in an increased risk of injury and falls as well as heart disease, Type 2 diabetes, obesity, high blood pressure and a weakened immune system, past research shows.Artificial light at night already harms wildlife, causing sea turtle hatchlings to travel toward dangerous, developed areas and contributing to bird fatalities in major cities.open image in galleryStars appear to rotate around the Kitt Peak National Observatory in Tucson, Arizona, in January 2026. Physicians and scientists warn that star-blocking light from satellites in low-Earth orbit could harm our sleep health (AFP via Getty Images)“Circadian rhythms are present in all types of organisms, ranging from bacteria to plants to animals, including humans. These rhythms synchronize physiological function to the natural light-dark cycle, which is important for overall well-being,” Kristen Knutson, an associate professor of neurology and preventive medicine, said in a statement. “Light at night will disrupt these rhythms, which can impair health and well-being.”The experts warned that recent plans from California aerospace start-up Reflect Orbital could flood entire cities with daylight-level light. Reflect Orbital plans to use large, mirrored satellites to redirect sunlight to Earth at night.Reflect Orbital did not immediately respond to The Independent’s request for comment on Thursday, but the company told Space.com last year that it would use an upcoming demonstration mission to limit any possible negative effects of the reflected light. A spokesperson said that the service is localized and would tilt away from the planet’s surface once it has passed the region."During the 2026 demonstration, observers at designated test sites will see the reflection as a bright moving star," a spokesperson for the company said. "The illuminated area on the ground will be a soft, moonlike glow."But astronomers had concerns about light from sunlight-reflecting satellites long before Reflect Orbital applied for a license to launch from the Federal Communications Commission last year.Some of these satellites are extremely bright - bright enough to alter the night sky forever, according to astronomers. “There are only 1,000 stars you can see with the unaided eye. Adding 400,000 bright satellites that move could completely change the night sky,” University of Illinois Urbana-Champaign aerospace engineer Siegfried Eggl said in 2023.The satellites will be brighter than Saturn, Peter Plavchan, an associate professor of physics and astronomy at George Mason University, told Scientific American in a conversation regarding the launch of operator AST SpaceMobile’s BlueBird 6 satell