Tech giants like Elon Musk's SpaceX and Jeff Bezos' Amazon have plans to launch constellations of thousands of satellites aimed at providing global internet access. But astronomers are worried that adding the masses of satellites to Earth's orbit could screw up our view of the night sky, as well as disrupt scientific research.
The Astronomical Union International — the world's largest organization of professional astronomers with over 13,000 members — issued a statement last week to complain about SpaceX's launch of its first batch of satellites at the end of May. While that launch only sent about 60 satellites into orbit, SpaceX eventually plans a network of satellites, called Starlink, that would consist of nearly 12,000 satellites flying in low Earth orbit (within 1,200 miles of the planet's surface). Roughly half of those satellites are reportedly expected to launch within the next six years.
And SpaceX isn't the only company launching satellite networks, as Amazon has a similar plan in the works, called Project Kuiper, that would put over 3,200 satellites in low Earth orbit over several years in order to provide broadband internet access around the world.
In its statement, the IAU argues that an uncrowded night sky is "not only essential to advancing our understanding of the Universe of which we are a part, but also as a resource for all humanity and for the protection of nocturnal wildlife," the statement reads. "We do not yet understand the impact of thousands of these visible satellites scattered across the night sky and despite their good intentions, these satellite constellations may threaten both."
The IAU's statement came after some astronomers — both amateur and professional — took to social media following last month's SpaceX Starlink launch to voice their own concerns. Dutch scientist Marco Langbroek tweeted a video showing the Startlink satellites streaking across the night sky, though reports noted that the satellites would eventually drift apart (and into higher orbit) rather than being clustered together as they appear in the video.
Soon after, an astronomer at the Harvard-Smithsonian Center for Astrophysics, Jonathan McDowell, tweeted that the Starlink satellites were "brighter than we had expected," while Southwest Research Institute planetary astronomer Alex Parker wrote in a tweet Langbroek's video "gives me pause" because the satellites' brightness.
"If SpaceX launches all 12,000, they will outnumber stars visible to the naked eye," Parker wrote on Twitter.
Amazon did not immediately respond to CNBC Make It's request for comment.
In a statement provided to CNBC Make It, a SpaceX spokesperson said the company continues to monitor its orbiting satellites while noting that "the observability of the Starlink satellites is dramatically reduced as they raise orbit to greater distance and orient themselves with the phased array antennas toward Earth and their solar arrays behind the body of the satellite."
However, in a series of late-May tweets, Musk claimed that the current thousands of satellites in orbit pose little to no problems for astronomers, and that SpaceX is working to ensure its satellites will not hurt the view of the night sky. "We'll make sure Starlink has no material effect on discoveries in astronomy," Musk wrote. "We care a great deal about science."
In fact, Musk also said that he had asked SpaceX to reduce the brightness of future Starlink satellites, and SpaceX has worked with the U.S. National Science Foundation, which oversees the National Radio Astronomy Observatory, to help ensure that the Starlink satellites do not run afoul of "international radio astronomy protection standards," the NSF said in a statement this week.
"NSF is aware of concerns from the research community and looks forward to careful analysis of potential impacts on optical and infrared astronomy," a spokesperson for NSF said in a statement provided to CNBC Make It. "NSF's mission is to fund basic research, as well as the instruments and facilities that enable such research. We value input from stakeholders about possible impacts on any area of the research ecosystem and will work with our federal, private and academic partners to ensure research capabilities are safeguarded."