Dead satellites and other debris are constantly burning up as they fall out of Earth’s orbit.
Conventional wisdom is destroying all that space junk is good, because it keeps orbit less cluttered. But it may have harmful effects on our planet’s magnetic field, as plasma physicist and former Air Force research scientist Sierra Solter — the author of a contentious and yet-to-be-peer-reviewed paper — argues in a new essay for The Guardian.
Ventures like Elon Musk’s SpaceX are launching thousands of satellites into orbit, and tens of thousands more are soon to follow as interest in the private space industry and space tourism continues to grow.
But having retired satellites burn up in the Earth’s atmosphere just might have disastrous effects on our planet, disturbing the plasma that forms a protective shell around it, shielding humanity from harmful radiation.
“After studying the problem for over a year, I have no doubt that the sheer vastness of this pollution is going to disrupt our delicate plasma environment in one way or another,” Solter wrote, arguing that big money in “commercial space ventures” could stop us from “discussing this potential crisis.”
Strip Show
Companies like SpaceX have long argued that satellites burning up during reentry into the Earth’s atmosphere is a harmless process. Solter, however, believes this practice releases huge amounts of metallic ash, more than “an Eiffel Tower’s worth” a year, directly into the ionosphere.
This ash, especially particulates of aluminum, could wreak havoc on — or even punch new holes into — the atmosphere’s ozone layer, potentially leaving humanity exposed back on the ground.
“If all of these conductive materials accumulate into a huge layer of trash, it could trap or deflect all or parts of our magnetic field,” Solter argued in the opinion piece. “The Earth is a ball magnet that we’re surrounding with fast-moving metal trash.”
“People like Elon Musk and Jeff Bezos repeatedly state that space is the key to human longevity,” Solter wrote. “But what if it is the opposite? What if the space industry is the means to our pale blue dot’s demise?”
“Until this pollution is studied further, we should all reconsider satellite internet,” she concluded.
Rise From the Ashes
SpaceX’s massive constellation of satellites are an eye-grabbing spectacle, but they’re also the center of great controversy, ranging from concerns about space junk to astronomers complaining they’re blocking their observations of the sky.
Now, a contentious and yet-to-be-peer-reviewed paper has suggested an even more catastrophic consequence of the Starlink network. As its satellites and others burn up in our atmosphere, their magnetized “dust” could pollute our atmosphere and weaken our planet’s magnetic field, which extends thousands of miles into space and shields us from dangerous cosmic radiation.
“I was shocked at everything that I found and that nobody has been studying this,” the author, University of Iceland doctoral student Sierra Solter-Hunt, told Live Science in a new interview. “I think it’s really, really alarming.”
Genuine Particle
Solter-Hunt estimates that it’s possible that the amount of metallic particles in our atmosphere has increased by a millionfold since the start of the space age.
As more commercial satellites are launched and then burned up in the coming decades, that tally could reach a billion fold, she told Live Science, with most of the dead satellite dust accumulating in an upper region called the ionosphere that extends up to 400 miles above Earth — “and it could just stay there forever.”
This could form a “perfect conductive net around our planet” that if electrically charged, would block our protective geomagnetic field from extending past the ionosphere. In the “most extreme case,” the outer edges of our atmosphere, no longer fully protected by the geomagnetic field, would be stripped away by the harsh radiation of space over centuries.
Junk Science
Could the disintegrated remains of a few hundred thousand satellites really be enough to radically alter the Earth’s mighty magnetic field? Many experts are skeptical.
“Even at the densities [of spacecraft dust] discussed, a continuous conductive shell like a true magnetic shield is unlikely,” John Tarduno, a planetary scientist at the University of Rochester, told Live Science, calling some of the paper’s assumptions “too simple and unlikely to be correct.”
It’s also not clear if there will ever be that many satellites in orbit. SpaceX has launched nearly 6,000 so far, and Amazon plans to compete by eventually deploying over 3,200 satellites of its own — huge multi-billion dollar projects that nonetheless come nowhere near the tally of up to 1,000,000 that Solter-Hunt based her assumptions on.
Still, others argue there’s merit to the work. If nothing else, it underscores just how little we know about metallic pollution in our atmosphere, or how these satellites could affect the health of our planet.
“This is not an issue to be ignored,” Fionagh Thompson, a physicist at Durham University in England told Live Science. “There is a need to step back and view this [space junk pollution] as a completely new phenomenon.”
Noisy Orbit
SpaceX’s gigantic and growing Starlink satellite constellation is making astronomers absolutely miserable by showing up as bright streaks in their observations.
Scientists have for years complained about Starlink constellations to that end, but a new study published in the journal Astronomy & Astrophysics suggests the satellites are introducing yet another confounding factor to their observations: “unintended” radiation from the electronics onboard the satellites.
These electronics are emanating low-frequency radio waves, which are being picked up by telescopes designed to scan that frequency range. That’s because this range also happens to be instrumental to deep space observations.
According to the researchers, nearly 50 Starlink satellites were detected emanating this “unintended” radiation, and they expect similar detections from satellite constellations run by other companies, too — not just SpaceX.
Megahertz Mess
In this case, the radiation was detected by the Low Frequency Array (LOFAR) telescope in the Netherlands, normally intended to pick up the extremely faint signals emitted by cosmic objects.
“With LOFAR, we detected radiation between 110 and 188 MHz from 47 out of the 68 satellites that were observed,” co-author Cees Bassa, an astronomer from the Netherlands Institute for Radio Astronomy (ASTRON), said in a press release.
“This frequency range includes a protected band between 150.05 and 153 megahertz specifically allocated to radio astronomy by the International Telecommunications Union,” he added.
The researchers note that SpaceX isn’t in violation of any laws, however, since there are no international regulations covering this form of radiation from satellites, unlike with terrestrial equipment.
But given the chaos Starlink satellites are causing, there likely should be. Follow-up simulations conducted by the researchers show that the effect of this radiation only gets markedly worse the bigger a constellation gets.
“This makes us not only worried about the existing constellations, but even more about the planned ones,” said co-author Benjamin Winkel, an astronomer at the Max Planck Institute, in the release.
Growth Spurt
Those fears are definitely warranted. Right now, SpaceX alone has around 4,000 Starlink satellites in orbit — and it has already received approval from the Federal Communications Commission for nearly 12,000 in total.
SpaceX has even pressed the FCC to raise that limit to 30,000, but the regulator, for now, has balked at that immense number after NASA expressed its concerns over the risks those satellites could pose to spaceflight missions.
Yet, those numbers are from just one company, and we haven’t even considered Amazon’s plans to launch some 3,000 satellites of its own to compete with Starlink.
It doesn’t look like there’s any stopping more of these artificial constellations from cluttering our skies. But for now, the researchers say they’re in close contact with SpaceX to discuss ways to minimize the impacts on astronomy.