The launch of NASA's Artemis II mission in April 2026 caused significant disturbances in Earth's ionosphere that could have triggered temporary, localized errors in GPS positioning, a new study has found.
The study, by a team of researchers from National Cheng Kung University in Taiwan, analyzed data from high-precision networks of fixed, ground-based GPS receivers, used by U.S. scientific institutions to measure the minuscule motions of Earth's tectonic plates in the lead-up to earthquakes. By measuring how long it takes GPS signals to travel from space to ground stations, the researchers were able to reconstruct how the passage of the Artemis II mission's Space Launch System (SLS) rocket changed the concentrations of free electrons in the ionosphere — the electrically charged layer of Earth's atmosphere at altitudes above 30 miles (50 kilometers).
The measurements found that the ionospheric disturbances resulting from the sheer power of the Artemis II launch were more significant than any caused by other rocket launches to date and up to ten times more intense than those observed following the test launches of SpaceX's Starship, which is twice as powerful as the SLS based on liftoff thrust.
During the mission's launch, ground-based GPS stations detected changes in the ionospheric electron density equivalent to positioning errors of several meters. Such inaccuracies could easily throw self-driving cars off track, potentially causing traffic collisions, according to Charles Lin, an earth science professor at National Cheng Kung University and one of the co-authors of the paper.
"A positioning error of a couple of meters is enough to cause an autonomous car to change lanes," Lin told Space.com. "It could have a strong impact not only on self-driving cars but also on drone positioning."
NASA's SLS rocket lifts off during the launch of the Artemis II mission on April 1, 2026 from Kennedy Space Center in Florida. (Image credit: NASA/Joel Kowsky)
GPS receivers determine their position on Earth's surface at any single moment by measuring their distance to four different GPS satellites. When concentrations of free electrons in the upper atmosphere change — for example during a solar storm or after a rocket passage — the signal reaches Earth either faster or more slowly, resulting in inaccurate measurements.
Satellites of the U.S. GPS constellation and other Global Navigation Satellite Systems orbit Earth at an altitude of around 12,550 miles (20,200 kilometers), far above the upper edge of the ionosphere, meaning the positioning, navigation and timing signal these satellites transmit must pass through this volatile atmospheric layer to reach Earth.
Severe solar storms can disrupt GPS signals for days by dumping energy into the atmosphere in the form of charged particles from the sun. The impact of rocket launches, triggered by the supersonic flight of the rocket body through the high-altitude air, is much more short-lived. As the rocket soars up, it creates a shock wave, which virtually punches a hole into the ionosphere.
In the aftermath of the Artemis II launch, the researchers observed two such holes — one left behind by the 212-foot-long (65 meters) SSL core stage, and the other caused by two subsequent thruster burns of the rocket's upper stage. In both cases, these holes stretched across the American continent from East to West like giant 3,100-mile (5,000-kilometer) contrails.
The solid rocket boosters of NASA's SLS rocket ignite during the launch of the Artemis II mission on April 1, 2026 from Kennedy Space Center in Florida. (Image credit: NASA)
Despite the enormous power of the SLS core stage, the disturbance caused by the second-stage burns directly inside the ionosphere was far more prominent.
Those two burns, at altitudes around 115 miles (185 kilometers), took place more than an hour after lift-off and allowed the Orion capsule to break free from Earth's gravity and head for the moon.
"Rocket launches from the ground to space produce that kind of effect, but we have never seen this kind of orbital maneuver in an interplanetary mission," said Lin. "In the future, as we are going to see many more missions going to the moon and to Mars, these space weather effects will become much more significant."
Newly released photographs of the sun captured during the Aug. 12 total solar eclipse reveal the sun's outer atmosphere in unprecedented detail.
The images, released by researchers working as part of the Solar Wind Sherpas project coordinated by the University of Hawaii, also show rare structures in the solar wind known as smoke rings. Named for their resemblance to the circles blown by smokers, these vortices were first identified in solar eclipse photographs captured in 2008. The researchers had long struggled to explain the processes behind their formation. They now know the rings are a result of the temperature differences in the coronal plasma and spread along the sun's magnetic lines deep into interplanetary space.
"This year, we have managed to capture those smoke rings really well," Miloslav Druckmüller, a professor of mathematics at the Brno University of Technology in the Czech Republic, who leads the image processing efforts for the Solar Wind Sherpas Team, said in a statement. "They are beautifully twisted vortices and there are very many of them in the corona."
The images, taken from the Pico Trigaza mountain in Spain, also reveal a giant coronal hole — an opening in the sun's magnetic field lines — through which solar wind can escape more readily at very high speedsof up to 500 miles per second (800 kilometers per second).
Coronal holes are cooler regions in the sun's atmosphere that appear darker in extreme ultraviolet and X-ray images taken by probes in space. They form in regions where the sun's magnetic field lines extend outward into space rather than looping back to the surface, allowing high-speed solar wind to escape. These structures can persist for weeks or even months.
High-res images of the sun taken during the total solar eclipse of August 2026 reveal a coronal hole and intriguing structures known as smoke rings in the solar corona. Click the right arrow for an annotated version.Brno University of Technology/Miloslav DruckmüllerAnnotated high-res images of the sun taken during the total solar eclipse of August 2026 reveal a coronal hole and intriguing structures known as smoke rings in the solar corona.Brno University of Technology/Miloslav Druckmüller
Solar eclipse photography provides a unique vista into the processes taking place in the sun's upper atmosphere, the corona, which remain hidden even to cutting-edge space-based observatories.
Space probes and astronomical telescopes on Earth rely on instruments known as coronagraphs to view the corona. As the corona is a million times dimmer than the sun's surface, researchers need to obscure the visible solar disk with an occulter to view it. This occulter, located inside the telescope, has to cover a larger area than just the solar disk itself to protect the images from the effects of diffraction.
During a total solar eclipse, the moon naturally blocks the sun's bright disk, allowing scientists to capture exceptionally detailed views of the inner corona that are difficult to obtain with conventional coronographs.
Technologies developed and tested in orbit to remove space junk and fix broken satellites can be speedily repurposed to build fleets of bodyguard spacecraft to protect important satellites from adversary attacks, space clean-up company Astroscale thinks.
Astroscale made history with its 2024 up-close in-orbit inspection of a discarded Japanese rocket stage during the pioneering ADRAS-J mission in low Earth orbit (LEO), the region of space below altitudes of 1,200 miles (2,000 kilometers).
The firm's ELSA-D mission, which ran from 2021 to 2024, was the first commercial endeavor to demonstrate orbital capture technologies in LEO. Now, this technology can come in handy as Western space assets face increasing threats from Russia.
Speaking on the sidelines of an event in London earlier this month, Alex Godfrey, Astroscale's head of defense, said the company could have a protector spacecraft ready for launch in under three years.
"In in-orbit servicing, we have to achieve very high levels of agility to be able to dock and close to a distance of zero meters to refuel something or remove it from orbit," Godfrey told Space.com. "With space control, you're rarely getting quite as close, so in some ways it's simpler because you are further away."
Space control — a military term for ensuring the space around Earth remains orderly and peaceful — is quickly becoming a hot talking point. Godfrey's remarks came just as the world witnessed in shock as Russia made close-up maneuvers around a radar satellite owned by Finland headquartered Earth-observation company ICEYE. The October incident, described by experts as the first rendezvous of two active satellites in low Earth orbit conducted without the consent of the target, raised concerns Russia may be preparing to damage the satellite, which is part of a fleet providing critical intelligence to Ukraine.
U.S. Under Secretary of State Thomas G. DiNanno described Russia's actions on X as "threatening behavior" and "consistent with on-orbit weapons operations."
The ICEYE incident is only the latest in a long string of activities conducted by Russia in space designed either to eavesdrop on or interfere with the activity of critical Western space assets. The Luch-1 and Luch-2 satellites have been stalking Europe's and America's communications satellites in geostationary orbit — the busy region 22,000 miles (36,000 km) above the planet where satellites have a fixed view of a portion of the globe—since 2014. Germany's military space command chief Major General Michael Traut admitted earlier this year that the Luch spacecraft have been spying on European strategic communications in space for years.
Russia's Luch-2 satellite approaches another geostationary satellite on April 12, 2024 as tracked by ground-based observation stations. (Image credit: Aldoria)
A bodyguard satellite would make sure no such intruder gets dangerously close. Godfrey said that the cost of a bodyguard mission would be on the order of a single percent of the value of a military-grade geostationary communications constellation such as the U.K.'s £8.4-billion Skynet fleet.
"To build a bodyguard satellite is absolutely within the capability and the budget of a single country like the U.K.," said Godfrey. "It would be similar to a carrier strike group where you have a [naval aircraft] carrier, but that carrier never leaves the port on its own. It has an escort of much smaller, lower-cost systems that move around to protect it."
Although Astroscale, headquartered in Japan but with significant presence in the U.K., is a leader in the commercial orbital rendezvous and proximity operations technology, no Western players currently match the deployed capabilities of Russia and China. Europe, in particular, is under-equipped for defense and military operations in space, according to the Secure World Foundation's Global Counterspace Capabilities Report.With Russia's accelerating orbital forays, the clock appears to be ticking.
Godfrey proposes a pan-European fleet of orbital bodyguards patrolling clusters of European assets to ward off future Russian attempts to jam or damage the satellites.
"The UK, for example, has multiple assets in different positions around the geostationary ring," Godfrey said. "That is difficult to protect with a single spacecraft. So what I encourage nations to think about is how to form a geo-patrol force through collaboration. If France has assets in a similar location to the UK and maybe Germany, then it makes sense for one spacecraft to protect two or three allied spacecraft, and then, in another region, another country takes responsibility for the protection."
Nick Shave, the UK managing director at Astroscale, told Space.com that the company sees interest in its technologies and is "in discussions" with "companies and customers across Europe" although it has not signed any contracts to develop bodyguard satellites.
"We have spent a good amount of time talking over the last few years, but now we have to go and really deliver," Shave said. "The UK government is promising funding for space control development from 2030 onwards. So what needs to happen now is really preparing the ground so that we've got the right capabilities, the right investment and the right demonstrator capability, by 2030."
In the meantime, Russia's COSMOS 2612 stalker satellite keeps lingering 298 miles (480 km) from the ICEYE intelligence satellite in LEO, keeping the Western space community on edge.
The space around Earth is turning into a junkyard. Researchers think a refundable deposit scheme could force satellite operators to clean up their act before a tipping point is reached.
For years, space sustainability experts have warned that the growing number of satellites in orbit and the quantity of dead metal left behind threatens to trigger a dangerous cascade of collisions known as the Kessler Syndrome. Predicted in the 1970s by NASA physicist Donald Kessler, this chain of orbital smashups could make the space around Earth unusable and unsafe.
The dangerous tipping might be nearer than some think. Humankind's utilization of space is at an inflection point, as companies such as SpaceX, Blue Origin and Amazon plan to launch constellations of hundreds of thousands of telecommunication satellites and orbiting data centers in the coming years.
"Low Earth orbit looks like lots of other resources that we have trashed as economic actors," Daniel Kaffine, a professor of environmental and resource economics at University of Colorado Boulder, told Space.com.
"Waiting until it gets really, really bad to start implementing any of these types of policy interventions has historically been what we have done," Kaffine added. "But maybe we can think about things we can do right now."
In a paper published last month in the journal Nature Communications, Kaffine and his collaborators propose a scheme that would require satellite operators to post a bond of $200,000 before launch, refundable with interest upon the completion of a successful deorbit. Companies that fail to remove their junk would lose the money, which could go toward a shared pool funding active debris-removal missions, the researchers said.
"You could possibly raise billions of dollars by that," said Kaffine. "We think it's a very neat policy that doesn't require international coordination."
International bodies, such as the Inter-Agency Space Debris Coordination Committee, ask satellite operators to remove their spacecraft from orbit within 25 years after the mission's end. The American Federal Communications Commission (FCC) imposes an even stricter standard — a five-year requirement for satellites in low Earth orbit. Still, a staggering 60% of satellites remain in place when their propellant runs out, the researchers say, as no consequences ensue if they fail to deorbit.
Solving the problem on the international level would be difficult, as international bodies have no powers to enforce compliance. Moreover, the United Nations Committee on the Peaceful Uses of Outer Space (COPUOS), which sets down rules for the peaceful exploration of outer space, requires the unanimous support of every member state to pass new regulations, which is nearly impossible to achieve.
"The policy we propose could be implemented on a national level, which is why we think it's interesting," Indigo Brownhall, a space sustainability researcher at University College London and the paper's lead author, told Space.com. "Any country in Europe can request satellites registered with them to follow this bond policy."
To put it simply, no satellite registered in a given country gets to space before putting the money into the kitty. The researchers acknowledge that it might be hard to persuade major players historically averse to regulations, such as the U.S., to roll out such a scheme. But they say a more environmentally conscious block, like the European Union (EU), could enforce compliance by limiting market access to those who observe their rules.
"The consumer market in Europe is massive, like 300 to 400 million people," Brownhall said. "And the EU can request anyone who wants to sell space data or any products in the EU to follow their rules. They did this with GDPR [General Data Protection Regulation]. And you can imagine that somebody like Starlink [SpaceX's satellite-internet subsidiary] surely wants to sell Starlink terminals to Europeans."
The authors estimate that, even if the scheme only covered 20% of global satellite launches, it would reduce the number of derelict satellites careening around the planet by 18%.
An old rocket body tumbles in space above Earth as seen from Japan's Astroscale ADRAS-J satellite. (Image credit: Astroscale)
Currently, more than 57,000 pieces of space debris larger than 4 inches (10 centimeters) hurtle around Earth completely out of control, according to estimates by the European Space Agency. That's double the figure from less than 10 years ago. Most of these fragments were generated by explosions and orbital collisions that shattered satellites and used rocket stages into clouds of dangerous debris.
"Leaving big satellites that no longer work up there is like a ticking time bomb," Brownhall said. "Active satellites can move out of the way, but when two derelict satellites are going to hit each other, there is nothing you can do but watch it."
Kaffine said the policy could be modelled on U.S. oil operators' bond scheme, in place since the 1960s, which ensures that oil giants plug used oil wells after ceasing extraction.
"If the oil operators clean up after completing the oil production job, they get the money back," said Kaffine. "If they don't, the money goes into a fund, which the government then uses to clean up orphan wells. It's quite an analogous situation to what we see in space."
In the meantime, evidence of the worsening orbital situation is coming thick and fast. Space situational awareness companies such as U.S.-based LeoLabs, which use networks of ground-based radars and telescopes to monitor traffic in space, report increasing numbers of disintegration events — incidents involving either an explosion or a collision between old satellites, fragments and rocket bodies. In the past six months, LeoLabs has reported at least four fragmentation events in space, which together created hundreds of new pieces of space debris.
For decades, researchers have been monitoring armed conflict around the world by analyzing news reports and collecting oral testimonies. This approach, while valuable, has its limitations. A new study suggests that a satellite's view from above might fill the gaps in our understanding of the grim realities of war.
In 2017, the Myanmar Army murdered several hundred Muslim Rohingya civilians in the village of Chut Pyin near the country's western coast. Reports of the massacre in the settlement of about 2,000 reached the world through the testimonies of survivors who fled to neighboring Bangladesh. The massacre was part of a years-long campaign of brutality against the Muslim minority conducted by the Buddhist-run state. Satellite data later showed that houses in the predominantly Rohingya neighborhood were burned down by the Myanmar military during the atrocity, providing undeniable proof that the ethnic minority was targeted.
The incident is one of many demonstrating the advantage of adding views from space into conflict research, study lead author Valerie Sticher, a political science researcher at the University of Zurich in Switzerland, told Space.com.
"We have huge data sets about wars around the world going back 40 years," Sticher said. "But those datasets are based mostly on media reports. And these reports are not always available and not always reliable. Media can have biases and often focus only on certain types of violence."
For example, human reporters are more likely to focus on the numbers of people killed rather than the number of houses destroyed, she said. Satellites, on the other hand, provide a broad sweep over vast areas of land and, crucially, revisit the same location repeatedly. They can reveal patterns in conflicts and trends that could otherwise go undetected, while providing an overview of areas controlled by authoritarian regimes.
The researchers are now developing a methodology to integrate satellite observations into conflict research and create automated image analysis pipelines that would generate early warnings and alert the world to what's happening on the ground.
"Automated satellite data analysis would allow us to respond faster," said Sticher. "For example, in Myanmar, the area affected by ethnic cleansing was closed to independent journalists and investigators. Satellite data was the earliest reliable information to reach the outside world."
A SkySat Earth-observation satellite operated by the California company Planet spotted the wreckage of a failed launch out of Iran's Imam Khomeini Space Center on Aug. 29, 2019. (Image credit: Planet Labs, Inc.)
Hannes Mueller, a conflict researcher at the Spanish National Research Council, said that totalitarian governments can be very good at preventing information about atrocities from reaching the world. However, they can hardly fool satellites.
"In Myanmar, for example, when the military clears villages, they frequently kill everybody in those villages," he said. "Then you don't have any eyewitnesses for you to find out what's going on. But they usually also destroy the entire village, and so the violence leaves a mark from space."
Mueller was not involved in the new study but has used satellites in his work since the conflict in Syria in the early 2010s. He lauds the new paper for trying to "plot the road" for a more systematic integration of satellite data into conflict-monitoring data sets.
"Imagine we could generate a data stack of the entire world of all housing destruction since 2020 without any gaps in it," he said. "That would be a complete breakthrough!"
But satellites, too, have their limitations, he said. Currently, spacecraft must be tasked to take images and beam them to Earth. Because of the limited download availability, they can't image every spot they fly over, meaning they usually only reveal the aftermath of catastrophic incidents. For example, the Syrian city of Homs only became the focus of satellite imaging campaigns after the Syrian military attacked it with heavy artillery to suppress pro-democracy protests.
"There are no images of Homs before it got attacked," said Mueller. "There is no archival data of the city from before. Then, after the attack, you suddenly get lots."
In the future, onboard AI image processing — which some of the commercial satellite Earth-observation companies have already rolled out — might solve the problem. Machine learning algorithms running on computers on board the satellites will be able to detect incidents of potential interest and autonomously select significant images to send to the ground.
But there are other concerns. Just as authoritarian regimes can deny access to warzones to independent journalists, governments can order Earth-observation companies to restrict access to images of specific areas. In fact, the U.S. government did just that earlier this year when it ordered American commercial Earth-observation providers like Planet Labs to stop releasing high-resolution images of the Gulf of Oman and the Strait of Hormuz amid the escalating conflict in the region. The U.S also asked Europe to delay releasing images of that region captured by the European Sentinel satellites by 24 hours.
"With that, we are back to the same biases that we have with the news reporting," Mueller said. "We need to think about infrastructure that would provide us with transparency. That would really be a revolution in conflict research."
The new study was published in the journal Nature on Sept. 9.
A team of researchers just chased a pair of reentering satellites in a private jet to learn about the pollution caused by space debris burning up in Earth's atmosphere.
The satellites in question were the European Space Agency's (ESA) Tango and Samba spacecraft, which once formed the Cluster constellation, together with the already de-orbited Rumba and Salsa. The quartet used to study the interaction of Earth's magnetic field with the solar wind. After 25 years of service, ESA took advantage of the Tango and Samba's controlled demise to help scientists learn what happens when satellites break apart and burn up during their spiral back to Earth.
The international team of researchers chased the two reentries, which occurred one day apart — on Aug. 31 and Sept. 1 — above the southern Pacific Ocean a few hundred miles from the Polynesian archipelago of Tonga.
Their goal was to understand what happens when satellites disintegrate and what chemical compounds arise in the process. Although companies such as SpaceX, Amazon and Blue Origin want to launch huge numbers of satellites to space in the next decade — SpaceX alone plans to loft 100,000 of its Starlink V3 spacecraft — very little is known about the effects of satellite reentries on Earth's atmosphere. Researchers are also still unsure which spacecraft burn up completely and how many fragments may reach the ground, putting lives and property at risk.
"We want to understand what happens to these bodies as they fly through the atmosphere, which causes friction and very high temperatures," Jiří Šilha, CEO of the Slovak company Astros Solutions, and one of the researchers aboard the plane, told Space.com. "We know that those satellites break up into fragments, which subsequently melt in the atmosphere."
The researchers chased the reentering spacecraft following exact calculations provided by ESA controllers, who were able to maintain connection with the spacecraft until the very last moment before they plunged into the atmosphere.
Researchers inside a private jet during a campaign observing the reentry of ESA's Cluster Tango satellite on Sept. 1, 2026. (Image credit: Jiří Šilha)
The satellite reentries, although they occurred during daylight, were visible from aboard the plane even to the naked eye, said Šilha, and created spectacular fireballs that lasted tens of seconds.
"Bolides and meteors only last a few seconds or less," said Šilha. "But satellites are slower. They enter the atmosphere at a shallower angle, and the atmosphere slows them down further."
But the researchers were there for science, not for a sky show. And it was a rare opportunity: The Cluster trajectories were so precisely known that the scientists could prepare for them and be at the exact spot at the exact time to witness those explosions from only a couple of hundred miles away.
The aircraft, a small commercial business jet, was packed with 30 cameras and spectrometers fitted with special filters to capture not only how the satellites disintegrated but also detect the spectral signatures of the chemical elements released as their bodies burned up.
Eight scientists were squashed on board the darkened jet operating the instruments through the aircraft's six windows as the pilots navigated to the vicinity of the spot where ESA analysts had predicted the breakup would occur.
"We were flying toward the object, and first it looked like a compact source of light as the material ablated," said Šilha. "At some point, there was a sudden explosion as the satellite disintegrated."
The plane allowed the researchers to overcome any clouds that could obscure the view from the ground, and also to bypass the thickest layer of the atmosphere, which would distort the measurements. As the satellites hurtled through the air, slowing down from the mind-boggling speed of 22,370 mph (36,000 kph) at which they hit the upper atmosphere, the jet approached them to within a distance of around 75 miles (120 kilometers).
"We begin observing it when it's at about 90 kilometers [56 miles] and it stops being visible at about 65 to 70 kilometers [40 to 44 miles]," Šilha said. "For about thirty to forty seconds after the explosion, you can observe an interesting structure as all those various fragments ablate in the atmosphere. Then they all either burn up or slow down."
Šilha said the cameras captured tens of fragments, in detail that had never been observed before.
The researchers also attempted to trace seven chemical compounds, including titanium, sodium and potassium, which get released as satellites burn up. The team was especially interested in aluminum, which makes up the majority of a satellite body. Aluminum is not naturally present in Earth's atmosphere and most likely forms aluminum oxide during the incineration. The potential presence of aluminum oxide in the atmosphere in higher concentrations worries scientists, as it could potentially trigger ozone depletion in the stratosphere.
"We tried to measure the aluminum at different altitudes, using specialized filters, which could tell us when this aluminum interacts with the atmosphere," said Šilha. "That's when the aluminum oxide likely forms, and that's something that has never been observed before. We don't know exactly how and in what quantities the aluminum oxide might be forming."
The researchers will now analyze the data to learn exactly what chemical reactions may be occurring during every second of the breakup and burn-up process. The data will help atmospheric physics and chemistry researchers improve their models to further our understanding of the potential damage the growing satellite industry might do to the planet and its climate in the future.
"The data will help us validate whether the models agree with reality," said Šilha.
The team previously chased the reentry of the first of the four Cluster satellites — Salsa — in September 2024. The lessons from that campaign helped the team get closer to the Tango and Samba spacecraft and obtain more and more accurate data.
Each of the sun-reflecting mirrors proposed by U.S.-based startup Reflect Orbital will appear 40 times brighter than the full moon to observers standing within its beam on Earth, a study has found. The light pollution produced by each of those mirrors would completely wipe out stars from the sky for those underneath them, turning the starry night into an eerie twilight zone.
"It will be worse than big cities like London," Gaspar Bakos, a professor of astrophysics at the University of Princeton and one of the authors of the study, told Space.com. "You would not see any stars if you were in the beam."
Reflect Orbital recently received a license from the U.S. Federal Communications Commission (FCC) to launch a demonstration satellite called EARENDIL-1 into an orbit 373 miles (600 kilometers) above Earth. The spacecraft will be fitted with a giant mirror 60 by 60 feet (18 by 18 meters) in size to test how sunlight can be reflected to Earth to extend the operations of solar power plants into nighttime hours or even to illuminate disaster zones after dark for free.
Despite the company's intentions, the FCC's decision stirred an outcry among astronomers, environmental campaigners, commercial pilot associations and other stakeholders, who fear the effects that might come to pass if the FCC approves Reflect Orbital's plan to launch 40,000 space mirrors even larger than EARENDIL-1 in the coming years.
Bakos is one of the astronomers who filed objections to the FCC against the plan. He said that the new study provides hard numbers on Reflect Orbital's impact where there previously were only rough estimates.
"There has been some disbelief from Reflect Orbital about our original estimates, so we have taken data on light scattering in Earth's atmosphere which is based on papers that go back for decades to calculate the light pollution," said Bakos. "These are scattering calculations that have been extensively tested in real life situations. So, we now have scientifically accurate renderings based on this paper."
Instead of focusing on EARENDIL-1, the researchers calculated the impact of Reflect Orbital's operational mirrors, which will be 174 by 174 feet (54 by 54 m) in size. They found that to observers on Earth standing at the center of the mirror's 3.4-mile-wide (5.4 kilometers) beam, the satellite would appear 40 times as bright as the full moon and the sky as luminous as that in the after-sunset twilight.
An illustration of Reflect Orbital's satellites in orbit. (Image credit: Reflect Orbital)
But thanks to atmospheric light scattering — the bouncing of photons off particles in the air — the area affected by the mirror's passage would be much wider, the study found. Even at a distance of nearly 9 miles (14 kilometers) from the beam, the sky would be brighter than when the moon is full. At a distance of 21 miles (34 kilometers), the light-polluted area above the horizon in the direction of the beam would still appear brighter than the night sky during a full moon.
That would be just a single mirror. But Reflect Orbital wants to fly 40,000 such satellites. Bakos said that data suggests that to trigger energy generation even in the most efficient solar panels of today would require the combined reflected light from at least 400 such mirrors at the same time. Together, the beam from those mirrors would be 10,000 brighter than the full moon, which, however, only makes up about 2.4 percent of the brightness of the sun, the paper states.
The sky glow resulting from these combined beams, the researchers found, would be visible from 50 miles away (80 kilometers), and extend the twilight zone up to 9 miles (14 kilometers) from the beam.
A rendering of the effect of Reflect Orbital's space mirrors on the night sky in a dark sky location. This image depicts a beam of light from one of the company's mirrors from roughly 8.5 miles (14 kilometers) away. (Image credit: Gaspar Bakos/Princeton University)
"It would be almost daytime brightness," said Bakos. "It would be just like before sunrise. But in fact, that's too low for solar panels to actually operate. Even the very best ones would barely turn on even with 400 mirrors illuminating the patch."
In renderings created by Bakos and his team based on the calculations, a pristine dark sky at a dark location is shown to completely transform into a star-free twilight zone as the mirror flies overhead.
Reflect Orbital's spokesperson told Space.com in response that the study's findings were based on "inaccurate assumptions" and insisted that "the vast majority of people will never see the light in their lifetime as the vast majority of service locations will be very remote," serving "large construction and solar projects in the middle of nowhere."
The spokesperson further added that "only the satellites required to serve approved locations would be active; inactive satellites would remain below naked-eye visibility."
The researchers, however, criticize the company for failing to provide technical data to back up their claims.
Reflect Orbital, however, insists that they "engaged substantively with legitimate concerns raised by astronomers, environmental researchers and scientists" and that such "feedback has informed our technology and operational plans."
The company says that they are "working on a coordination agreement with the National Science Foundation and commissioning third-party research through independent researchers and federal partners."
An illustration of the brightness of the full moon in a dark sky location. (Image credit: Gaspar Bakos/Princeton University)
For comparison, SpaceX's Starlink currently consists of around 11,000 satellites. According to some estimates, around 30 Starlink satellites are visible in the sky from a single spot on Earth at any point in time. Starlink satellites, however, are much smaller and dimmer than the Reflect Orbital mirrors.
Bakos said the overall effect of the mirrors would depend on the reflectiveness of the illuminated surface and the cloudiness of the sky. A forest, for example, might absorb most of the light while snow-covered fields or concrete city streets would scatter it further.
"It's not just the beam," said Bakos. "The glow of the reflected light from the surface will cause the sky to glow. For example the light pollution from a town illuminated by the beam will be ten to 20 times brighter than from the artificial lighting in that same town. Artificial light only illuminates streets and sidewalks, but here, everything would be illuminated — every backyard, park, roof or river."
The FCC received around 1,900 objections against the Reflect Orbital application. In its Order and Justification of Reflect Orbital's mission license, the agency stated that "impacts on optical astronomy fall outside [the FCC's] review and authorization."
In the U.S., satellite projects are exempt from the National Environmental Policy Act (NEPA), which requires federal agencies to assess environmental impacts of their decisions. The exemption has been in place since the 1980s when only a handful of satellites were being launched in a year.
The study was accepted for publication in the Astrophysical Journal and is currently available on arXiv.
An 8,800-pound (4,000 kilograms) Falcon 9 rocket stage hit the moon last Wednesday (Aug. 5), stirring lunar regolith in a massive plume of dust observable all the way from Earth.
The rocket joined some 3,000 manmade objects scattered on the surface of our planet's companion. Some experts think it's about time we start treating the pristine lunar environment with a bit more respect.
Around 200 tons of Earth stuff have been either deliberately left on or crashed into the moon since the beginning of the space age. Some of this material has a prominent place in history books: The descent modules from all six Apollo landing missions, Soviet Lunakhod rovers from the 1970s and China's 2010s Yutu 1 and 2 robots still sit where they had been left or ran out of power.
But there is also a lot of stuff on the moon that wasn't really meant to end up there. Astronomer and space historian Jonathan McDowell says that many rocket stages and other objects left in orbit between Earth and the moon since the first lunar missions in the 1960s may have ended up on the gray dirt. Four years before the Falcon 9 upper stage crashed near Einstein Crater, for example, part of a Chinese Long March 3C rocket slammed into the moon's far side. And experts think such incidents could become increasingly common in the coming years, as exploration of the moon intensifies.
"We're in a transitional moment," McDowell told Space.com. "From the era when there was rare lunar exploration mostly by the U.S. and the Soviet Union, we've seen over the past decade other nations landing on the moon and the beginning of commercial missions. But governance has not kept up with this. We don't have an international set of agreements on how to operate near the moon, how to coordinate activities near the moon, and we're really going to need it because, not only is the amount of activity at the moon increasing, but the number of different players is greatly increasing, too."
Human activities on the moon are governed by the 1967 United Nations Outer Space Treaty, Marieta Valdivia Lefort, a policy officer at the Royal Astronomical Society in the U.K., told Space.com. Article IX of that treaty binds countries to "conduct the exploration of outer space in a way that avoids harmful contamination," she said. But what exactly constitutes such contamination is unclear, she added.
"There are international legal frameworks that apply to activities on the moon and include obligations concerning harmful contamination, but there is no dedicated international 'waste law' or comprehensive 'rubbish-management' system for it," Lefort wrote in an email. "The Outer Space Treaty does not define when contamination becomes 'harmful.' It does not set numerical waste limits, create approved disposal sites or require every object on the moon to be removed."
South Korea's Danuri moon probe captured this photo of the spot where a SpaceX Falcon 9 upper stage hit the moon on Aug. 5, 2026. (Image credit: KARI)
The moon is big. Its surface area, around 14.7 million square miles (38 million square kilometers) rivals that of Asia, Earth's largest continent, which covers 17 million square miles (44 million square km). But the moon's low gravity — around 17% that of Earth — means the dust that an impact stirs up travels a long way and takes a long time to settle, McDowell said.
"It's not just a local event," he said. "It's an equivalent to a continental-level event. In the future, when you have permanent human bases and scientific experiments on the moon, you don't want rocket stages smashing into the moon on a regular basis, creating big plumes of dust that could contaminate instruments or disturb gravitational wave detectors."
Moreover, the artificial material introduced and the craters that arise when heavy rocket stages smash into the lunar surface are altering the lunar environment, potentially erasing yet unexplored scientific material.
"The moon is naturally struck by meteoroids, and those impacts form part of the geological record that scientists are trying to understand," Lefort wrote. "The main concern is the alteration of the moon's physical and chemical environment, particularly where repeated disturbances could damage or obscure valuable scientific evidence."
A Chinese rocket body impacted the moon on March 4, 2022, creating a double crater roughly 95 feet (29 meters), as seen in this photo taken by NASA's Lunar Reconnaissance Orbiter. (Image credit: NASA/GSFC/Arizona State University)
Gregory Radisic, a space law expert at Australia's Bond University, told Space.com that the Falcon 9 crash was timely, as it can stir debate about responsible behavior in space before the moon gets too busy.
"It's not by good planning that this didn't hit something important," he said. "It's by pure luck that we're only having a conversation about theoretical problems down the line and that this did not destroy a million-dollar experiment or an important site of scientific study."
He added that spaceflight companies may start paying attention to the risks only after human lives are lost or expensive infrastructure suffers, resulting in tangible fines and consequences.
"When there is a loss of life or a loss of investment, the industry will start to care," Radisic said. "As long as things are losing aesthetic or scientific value, the industry is not likely going to care."
The Falcon 9 rocket stage that hit the moon was left in a high-altitude orbit around Earth in January 2025, after it propelled Firefly Aerospace's Blue Ghost and ispace's Resilience landers to the moon.
McDowell explained that, as the rocket stage was left relatively close to the moon, it got repeatedly influenced by lunar gravity, eventually spiralling into its surface.
"If you leave [an object] in an orbit that's in this middle region that is far enough that the moon's gravity is affecting it but not far enough out to go into orbit around the sun, then that orbit is very hard to predict," McDowell said. "The orbital uncertainties multiply over many passes and, eventually, if you get unlucky, the moon tugs it into an orbit where it's going to hit either the moon or Earth in a completely unpredictable way."
McDowell said that, since the January 2025 launch, SpaceX has been pushing its moon-mission rockets farther out into orbit around the sun.
"I hope that we're going to see a new norm evolve, and that what we have seen now is not how you dispose of your rocket stages in the future," he said.
Concentrations of dangerous pollutants from rocket launches and satellite reentries in Earth's upper atmosphere might reach treacherous tipping points if constellations of hundreds of thousands of orbiting data centers get deployed in the next decade, experts say.
There's no question that Earth has an AI data center problem. By 2030, AI data centers may be responsible for up to 17% of electricity consumption in the U.S., according to a forecast by the Electric Power Research Institute. New fossil fuel power plants are being built to feed the growing demand for electricity, and aging ones are kept online despite decarbonization plans. On top of that, huge amounts of water are taken from already strained reservoirs to cool the computers.
Companies such as SpaceX, Amazon and Blue Origin say they have a solution: moving the power-hungry data crunching infrastructure into space, where solar power is easy to produce, and heat can be radiated out into the frigid vacuum. Combined, those companies have filed applications to the U.S. Federal Communications Commission to launch more than a million orbiting data centers in the next 10 years. Most of those will belong to SpaceX, if all goes to plan; Elon Musk has said the company wants to operate a million-satellite AI constellation all by itself.
The plans are making atmospheric scientists tear their hair out. If all these projects come to fruition, the number of satellites being launched to space and reentering the atmosphere will increase 100 times compared to today's numbers.
Moreover, the data center satellites will be much larger than the spacecraft orbiting Earth today. This large mass will translate into higher quantities of polluting propellant needed to loft these systems off Earth and a much larger amount of metals vaporizing in Earth's atmosphere during reentry. Neither is good news for our planet's air.
Pristine upper atmosphere
"Launches and the reentries are really the only things that humans do that deposit material directly into the upper atmosphere," Aaron Boley, an astronomy professor and space sustainability researcher at the University of British Columbia, told Space.com. "And the way things mix in the upper atmosphere means that the launch and reentry emissions are by far more impactful."
Most rockets emit black carbon, which could worsen global warming. Satellite bodies are mostly made of aluminum, which likely turns into aluminum oxide when burned in the presence of oxygen. Aluminum oxide is known for its ability to trigger ozone depletion, a hazardous process that was successfully thwarted by the Montreal Protocol of 1987.
Currently, scientists don't have a precise understanding of the chemical reactions that occur between the pollutants and the atmospheric gases at high altitudes. They also don't understand the tipping points, which may mean the difference between minor and major impacts on the climate. What is worse, pollutants in the upper atmosphere remain much longer than those emitted by cars and factory chimneys close to the ground.
"Close to the ground, we have rain and wind that removes pollution from the atmosphere within weeks," Eloise Marais, a professor of atmospheric chemistry at University College London, told Space.com. "If we put it into the higher layers of the atmosphere, we rely on very slow atmospheric processes to bring this pollution back down."
Too many launches
Black carbon from rockets, for example, can stay in the atmosphere for three years, scientists think, meaning its concentrations could dangerously rise in the near future.
SpaceX's Starship megarocket is likely to play a key role in the deployment of data center constellations. Unlike SpaceX's current workhorse launcher Falcon 9, which burns a form of the aviation fuel kerosene, Starship combusts the much cleaner combination of methane and liquid oxygen. But Marais cautions that Starship's size and the much more frequent launches that will be needed to deploy the vast constellations would result in an overall increase in the pollution injected into the upper atmosphere.
"Starship is a bigger rocket burning more propellant," Marais said. "So, in terms of each rocket launch, the difference almost offsets. It has potential per launch to produce quite similar amounts of black carbon."
Andrew Wilson, a space sustainability researcher at Glasgow Caledonia University in the U.K., told Space.com that every single Starship launch produces around 76,000 metric tons of carbon dioxide equivalent. That's about as much as 17,727 gasoline-powered passenger cars emit in a year.
And up to 77,000 Starship launches — some 15,300 per year — might be needed, according to estimates by Ars Technica, to deploy SpaceX's planned million-data-center constellation. That's a lot of rocket pollution added into the atmosphere. For comparison, there were just 324 orbital rocket liftoffs globally in 2025, according to Space News.
SpaceX's Starship megarocket launches on its 13th test flight, on July 24, 2026. (Image credit: SpaceX)
The space junk rain
Then there is the toxic ash from reentering satellites. Today, nearly 19,000 operational and defunct satellites orbit Earth, according to the European Space Agency. Currently, the most numerous type of satellite in Earth orbit is SpaceX's Starlink V2 Mini, each of which weighs about 1,760 pounds (800 kilograms). But SpaceX's orbital data centers are likely to be much more massive. Featuring solar arrays 246 feet (75 m) wide, every data center satellite might weigh up to 7.5 metric tonnes, according to available estimates.
Industry insiders expect that SpaceX and other providers would want to replace their AI satellites every five years with newer technology, as they do with existing communications satellites. As a result, tens or even hundreds of tons of metal may be reentering the atmosphere every year in the future, exceeding the amount of natural space rock that hits the planet.
The materials that satellites are made of are not naturally present in Earth's atmosphere, which means the consequences of such reentries can be unpredictable.
"Only 10 years ago, the reentries were not really a concern, because there were much more natural meteorites entering the atmosphere per year," Wilson said. "But if you have hundreds of thousands or millions of satellites in space at any one time, you are essentially going to create a rain of man-made materials, electronic equipment and metals that otherwise wouldn't be coming into the atmosphere."
He added that the situation is akin to ongoing climate change, which shows no signs of slowing down as humanity has so far failed to reduce carbon emissions.
"This is the most objects we've ever had in space, and we're continuing to propose more and more and more and more and more," Wilson said. "And there seems, in my opinion, to be very little consideration for the environment."
Not enough funding is currently flowing into research to answer the unknowns, Marais added.
"We need way more observations and way more time to be able to look into that," she said.
Boley concurred: "We absolutely have to understand, and we have to understand that before we actually launch a million satellites. Not that we launch them and wait [to see] what happens."
The plans of the satellite companies are stirring protests also among astronomers, who fear that the light pollution the constellations create will impact astronomical observations. A recent study by the European Southern Observatory concluded that, if all currently planned satellite constellation projects were to be built, astronomical research from the surface of Earth would no longer be possible.
The U.S. Federal Communications Commission (FCC) can single-handedly green-light massive spaceflight projects that could completely change the view of the night sky for the entire world. Despite the outcry these projects have caused, space law experts say there is very little other nations and the international community can do to thwart them if the FCC were to grant them licenses.
On July 10, the FCC approved an application by California-based Reflect Orbital to launch a 59-by-59-foot (18-by-18 meters) space mirror to test how to reflect sunlight onto solar farms on Earth after dusk. The decision has sparked outcry among astronomers and environmentalists who are concerned about the impact on global light pollution levels that Reflect Orbital's plans might have.
Opponents see the FCC's approval, despite hundreds of objections filed in response to the application, as an indication that the agency might eventually grant Reflect Orbital a license to fly an entire constellation of 50,000 such sun-reflecting mirrors. On top of Reflect Orbital's plans, companies including SpaceX, Blue Origin and Starcloud are awaiting the FCC's decisions on respective applications to deploy their own massive fleets of orbiting data centers and internet-beaming satellites. If all those projects come to fruition, the view of the night sky could change beyond recognition all over the world.
"The technology is outpacing the regulatory environment."
The United Nations' Outer Space Treaty conceived in the late 1960s lays down the international framework for the use and exploration of outer space. The document states that approvals for satellite projects are the domain of the nation in which those satellites are registered.
"The U.N. Treaty for Uses of Outer Space very well specifies that how many satellites are shot into space and how they are registered is a prerogative of the country in which they are registered," a source familiar with the operations of the United Nations Office of Outer Space Affairs (UNOOSA), who didn't wish to be named, told Space.com.
The states from which they launch, however, are responsible for any damage the satellites registered under their flags cause to other countries. But Ruskin Hartley, the CEO and Executive Director of the advocacy group DarkSky International, told Space.com that this liability provision only covers physical damage such as satellites colliding in space or spacecraft crashing down on Earth and damaging property.
"It hasn't been tested at all but most people don't think this damage extends to optical interference," Hartley said. "It would have to be physical damage. If a satellite reflects sunlight down and damages someone's observatory, that probably doesn't count as damage under the Outer Space Treaty."
In its Article I, the Outer Space Treaty states that "the exploration and use of outer space, including the moon and other celestial bodies, shall be carried out for the benefit and in the interests of all countries." But what exactly that means and what could be done if there is no consensus about those benefits is not clear at all.
The anonymous source told Space.com that UNOOSA and the UN-wide Committee on the Peaceful Uses of Outer Space (COPUOS) may discuss the issue, but despite the global consequences, are unlikely to come up with a mechanism to stop the corporations from doing what they want if the FCC backs them.
"These UN institutions were all started in the last century and are very slow," the source said. "They require unanimous consensus to pass anything and that obviously hardly ever happens. So nothing gets passed. By the time UN COPUOS and UNOOSA are done discussing anything, SpaceX will have launched another thousands satellites."
A rendering of Reflect Orbital's proposed constellation of mirror satellites. (Image credit: Reflect Orbital)
The European state of Slovakia in cooperation with the International Astronomical Union (IAU), in fact, submitted a paper to UN COPUOS in June calling for a "general prohibition on the use of space mirrors" or the development of "strong oversight mechanisms."
Aaron Boley, an astronomer at the University of British Columbia, who has been involved with the initiative, admits that these efforts are not likely to progress fast enough.
"There is indeed a major challenge right now with single states being able to create large changes to the sky and the orbital environment," Boley told Space.com in an email. "At the U.N. COPUOS, there are important steps being taken. But these agreements can be slow to achieve."
Hartley added that the companies pushing for grandiose space projects are taking advantage of existing legal loopholes that are not being effectively closed.
"These entrepreneurs that are pursuing these projects, either in the U.S. context as private entrepreneurs or in some instances in Europe and in China as government-level projects, clearly demonstrate that the regulatory environment and regulatory framework has significant gaps and holes in it," Hartley said. "Essentially, the technology is outpacing the regulatory environment."
Unilateral U.S. decisions
According to international space law and policy expert and former NASA legal council Robin J. Frank, this is not the first time the U.S. has pushed ahead with its agenda regardless of the concerns of the international community.
"This is not the first time the FCC has started down the route of unilateral decisions," Frank told Space.com. "Recently, for example, the FCC has approved direct-to-cell communication systems, which connect from a satellite directly to your phone, to use parts of the radio frequency spectrum that have not been authorized for that use by the International Communications Union. Their argument is that they are giving the U.S. industry a leg up."
The U.S., responsible for roughly 25 percent of the global GDP, has historically been reluctant to agree to binding international mechanisms that could restrict its actions, Frank added. Other major global powers, such as China or Russia tend to have a similar attitude, she said.
Currently, the U.S. is not even a party to the Paris Agreement, an international treaty that binds nations to work toward reducing their greenhouse gas emissions in order to curb global warming.
Frank added that individual nations could, for example, take action against constellations of orbiting mirrors by banning them from beaming light onto their territory at a threat of hefty fines. That however, is still not going to stop the development and mitigate the overall light pollution these satellites cause as they inadvertently reflect light as they zoom around Earth.
DarkSky International previously sued the FCC at the District Court of Columbia, challenging its decision to grant SpaceX a license to launch tens of thousands of satellites without conducting an environmental review. The court eventually rejected the non-profit's arguments, but Hartley said the advocacy group would consider filing another lawsuit if the FCC were to green-light the full Reflect Orbital constellation of 50,000 space mirrors or SpaceX's million orbiting data centers.
Despite the massive growth in the past decade, the satellite industry is exempt from the U.S. National Environmental Policy Act, meaning neither the FCC nor the satellite companies are obliged to prove their technologies will not be detrimental to the environment. That exclusion was put in place in the 1980s when satellite launches were few and far between. Many argue it's more than a high time to do away with it.
"It's a regulatory failure," Hartley said. "The ultimate fix is probably a legislative fix, or an administration that directs them to act differently. But this administration is not going to do that."
One hour of satellites over the northern Atacama Desert in Chile in October 2025. (Image credit: F. Kamphues, ESO/M. Kornmesser)
"This is an issue that's going to affect the quality of life for everybody on Earth."
A recent study by astronomers from the European Southern Observatory found that the brightness of the night sky would rise by up to 300 percent if all the currently planned constellations were to get deployed. That, the astronomers say, would be an end to astronomy as we know it.
Other experts pointed out that the need to have access to constant sunshine would force all orbital data center operators into a single narrow region of space, creating a bright "Saturn's ring" of satellites around the planet.
In its justification for granting the Reflect Orbital test flight license, the FCC stated that arguments about light pollution are outside its merit to judge. No other U.S. government agency, however, currently has a say over granting licenses to satellite companies.
On top of that, the air pollution from large quantities of re-entering satellites and the rockets that launch them risks damaging the ozone layer and altering the thermal balance of Earth's atmosphere, according to ongoing research. Greenhouse gas emissions released during launch and the manufacturing of the satellites may offset the advantages of putting data centers to space, extolled by the companies behind those plans.
"The industrialization of space is going to impact carbon in the atmosphere, through the launch phases of all these rockets, and it's very clear that the deorbit of these satellites is likely to change the composition of the atmosphere," Hartley said.
"This is more than just a niche issue for astronomers. This is an issue that's going to affect the quality of life for everybody on Earth."
