Two proposals sitting before the US Federal Communications Commission could fundamentally and irreversibly change what every human being, animal, and plant on Earth experiences every night. One startup wants to park reflective mirrors in orbit and beam concentrated sunlight onto specific patches of ground on demand. Elon Musk's SpaceX wants to deploy up to one million satellites to build a solar-powered artificial intelligence computing network above the atmosphere. Scientists representing approximately 2,500 researchers across more than 30 countries say both plans amount to a planetary-scale experiment with no off switch.
What Is Reflect Orbital Proposing?
The startup Reflect Orbital has applied to the FCC for permission to launch satellites equipped with large reflective mirrors capable of redirecting sunlight onto areas roughly 5 to 6 kilometers wide. According to the company's own materials, the illumination intensity would be adjustable "from full moon to full noon." Reflect Orbital says the system would only illuminate locations approved by local authorities, and it pitches the technology as a tool for extending solar energy generation into evening hours, supporting nighttime construction projects, responding to disasters, and boosting agricultural productivity.
The sales pitch sounds utilitarian. The scientific reaction has been closer to alarm.
SpaceX's One Million Satellite Plan
On January 30, 2026, SpaceX filed paperwork with the FCC seeking permission to deploy up to 1 million satellites into low Earth orbit, according to a filing reviewed by the American Astronomical Society. The stated purpose: build a network of space-based data centers powered by solar energy to run artificial intelligence workloads. SpaceX argues the system would reduce the energy and cooling demands of ground-based data centers, which have become significant consumers of electricity as AI infrastructure scales up.
The company already operates the largest active satellite constellation in history through its Starlink broadband network. This proposal would dwarf that effort by several orders of magnitude. There are currently fewer than 10,000 active satellites in orbit around Earth in total, across all operators and nations. SpaceX is asking for 1 million from a single company for a single purpose.
According to the American Astronomical Society's action alert on the proposals, the public comment period for Reflect Orbital's application closed in March 2026, while the FCC has not yet ruled on either application.
What Scientists Are Warning
The presidents of four major scientific organizations, the European Biological Rhythms Society, the Society for Research on Biological Rhythms, the Japanese Society for Chronobiology, and the Canadian Society for Chronobiology, jointly signed letters to the FCC expressing serious concern. Those four societies collectively represent about 2,500 researchers from more than 30 countries, according to reporting by The Guardian on April 5, 2026.
Their core warning centers on circadian biology. Nearly every organism on Earth, from humans to marine phytoplankton, uses the natural alternation of light and dark to regulate fundamental biological processes: when to sleep, when to produce hormones, when to migrate, when to bloom, and when to reproduce. The scientists say that artificially brightening the night sky, even modestly, could interfere with all of these systems simultaneously.
"The proposed scale of orbital deployment would represent a significant alteration of the natural night-time light environment at a planetary scale," the four society presidents wrote to the FCC.
Prof. Charalambos Kyriacou, a geneticist at the University of Leicester and president of the European Biological Rhythms Society, put the concern in direct terms. "We're saying, please think before you go through with this, because this could have global implications for things like food security. Plants need the night. You can't just get rid of it," he told The Guardian.
Prof. Tami Martino, of the University of Guelph and president of the Canadian Society of Chronobiology, added that the human instinct to judge brightness by what eyes can easily perceive misses the point. "Circadian systems are sensitive to light levels far below what humans typically perceive as bright," Martino told The Guardian.
The Existing Damage — and How Much Worse It Could Get
Even before either proposal moves forward, the existing population of satellites has already begun altering the night sky in measurable ways. Dr. Miroslav Kocifaj of the Slovak Academy of Sciences in Bratislava has modeled the effect and found that satellites and debris currently add between 3 and 8 microcandela per square metre to global night sky brightness. His projections, published and reviewed by The Guardian, suggest that figure could rise to between 5 and 19 microcandela per square metre by 2035 under current launch trajectories.
Ruskin Hartley, chief executive and executive director of DarkSky International, a nonprofit focused on protecting natural dark skies, noted in a statement that existing satellite numbers have already increased diffuse night sky brightness, what astronomers call sky glow, by roughly 10 percent. DarkSky International has also submitted a formal letter to the FCC opposing both proposals.
"While ideas like mirrors on satellites beaming 'sunlight on demand' to Earth or mega-constellations of up to 1 million satellites for AI datacentres may sound like science fiction, these proposals are very real," Hartley said.
Kocifaj underscored that this is not a problem wealthy countries can simply buy their way out of. "What I can say with confidence is that the phenomenon is real, that it is global and cannot be escaped by moving to a more remote location, and that it will increase substantially over the coming decade if current trends in satellite launches and debris generation continue," he said.
What Is at Stake Beyond Astronomy
Critics of satellite pollution often focus on the damage to astronomy, and that damage is real. Telescope images are already being degraded by satellite streaks, and the proposed SpaceX constellation would dramatically worsen that problem. But the scientists who wrote to the FCC are raising a broader set of concerns that go well beyond the ability to study distant galaxies.
Nocturnal animals navigate, hunt, and mate by the natural light of the moon and stars. Migratory birds use the night sky for orientation. Sea turtle hatchlings use it to find the ocean. Marine phytoplankton, which underpin the entire ocean food web, operate on light-dark cycles. Plants use photoperiodism, their ability to detect changes in day length, to time flowering and seed production. Artificially extending or brightening the night disrupts all of these systems, potentially with cascading effects on agriculture, fisheries, and ecosystems that remain poorly understood.
The scientists are not calling for an outright ban on either project. Their letter to the FCC urges regulators to require a full environmental impact review and to set strict limits on satellite reflectivity and on cumulative night sky brightness before approving any new large constellations.
The Regulatory Gap
The United States has no comprehensive framework governing how bright the sky above it can become due to commercial satellite operations. The FCC regulates spectrum use and orbital slots. The National Environmental Policy Act could in theory require environmental review of major federal actions, but whether the FCC's approval of a satellite license constitutes such an action has never been definitively settled for light pollution cases.
International treaties govern orbital debris and some aspects of satellite operations, but none set binding limits on sky brightness. The sky, in effect, has been treated as an unlimited dump for reflected light.
The American Astronomical Society has issued an action alert urging members of the public to submit comments to the FCC on both proposals, noting that regulatory decisions made in the coming months could shape the character of Earth's night environment for decades.
The scientists writing to the FCC are not opposed to innovation or to expanding access to solar energy or computing power. They are asking a simpler question: who decided the night sky belongs to the companies that can afford to launch things into it, and when did anyone ask the rest of life on Earth?