Last November, a satellite in low Earth orbit expanded to nearly 700 square feet, the size of a studio apartment.
The satellite, BlueWalker 3, has become one of the brightest objects in the sky, outshining some of the radiant stars in the Milky Way. A study published on Monday It’s the first of dozens of similar satellites being built by Nature — and AST Spacemobile, a company that aims to connect smartphones from orbit.
Astronomers are already worried about the appearance of megaconstellations of satellites like SpaceX’s Starlink, which have shiny surfaces that sometimes interfere with the view of space from the ground. The release and deployment of BlueWalker 3 has exacerbated those concerns.
“The problem isn’t necessarily a satellite,” said Siegfried Eckl, an astrophysicist at the University of Illinois and author of the new study, “but it’s a progenitor or prototype of a galaxy, so it’s happening. Eventually there must be a lot.”
Launched in September 2022, BlueWalker 3 is the precursor to AST Spacemobile’s Bluebird satellites, which aim to act as a network of orbital cell towers to “democratize access to knowledge and information for people regardless of where they live and work,” a spokesperson said. AST Spacemobile said. Last month, BlueWalker 3 was a success Released its first 5G connection For a smartphone in the range of cellular coverage on Earth.
AST Spacemobile is one of several companies racing to capture the growing demand for global broadband connectivity. SpaceX has sent about 5,000 satellites into space as part of its Starlink network, which already provides satellite Internet service. to customers All over the world. Other companies like Amazon (which is planned It launched its first prototype satellites on Friday) and OneWeb, have similar ambitions, and many countries are building their own communications megaconstellations.
“At the moment, there are 18 constellations planned around the world,” said Dr Eckl. “The total number of satellites they plan to put up there is an astounding half a million. That’s 100 times more than we already have.
The rapid proliferation of satellites in recent years has worried stars from all walks of life. As spacecraft move across the sky, they create bright trails and an ambient glow in the sky that can ruin astronomical images and obscure faint celestial objects visible to the naked eye.
“It’s going to be a big change with these galaxies,” said Jeremy Dreglon-Reid, an astronomer at the Universidad de Atacama in Chile and an author of the study.
AST made Spacemobile BlueWalker 3’s array the largest to provide strong cellular coverage directly to phones on Earth. The satellite is made up of several small antennas that can attach to existing smartphones, an approach that sets the company apart from Starlink and other planned satellites that currently rely on ground antennas or dishes.
To determine the specific impact of BlueWalker 3, the authors of the new study compiled satellite observations recorded by amateur and professional astronomers in Chile, the United States, Mexico, New Zealand, the Netherlands, and Morocco. This global campaign caused BlueWalker 3 to reach a magnitude that produced the same brightness as Procyon and Acheron, two of the 10 most luminous stars in the sky, according to the study.
“I really like how they used different telescopes from different parts of the world; it really highlights that this is a global problem,” said astronomer Samantha Lawler of the University of Regina in Saskatchewan, who was not involved in the study but wrote a paper in Nature. “A country, or a small company, launches a satellite that can be seen anywhere in the world.”
AST said it is working with astronomers on techniques to minimize spacemobile disturbances. It also contrasted the number in its constellation with the tens of thousands planned by other companies. It can “provide substantial global coverage with around 90 satellites,” the spokesman said.
Although the Bluebird satellites are very few in number, they are 64 times larger and brighter than the Starlink satellite. SpaceX orbiters are very bright during the first few days of deployment, but once they settle into their target orbits, they become very dim.
Astronomers expect the Bluebird satellites to remain bright in the sky for the rest of their lives. Consequently, one of these satellites may interfere with data captured by astronomical observatories.
“They are so bright that they destroy entire images recorded by large telescopes, such as the Vera Rubin Observatory, for example,” Dr. Eggl said.
Although many scientists and dark-sky advocates, including indigenous rights groups, have created rules, there are currently no regulations preventing companies from launching bright and massive satellites. And while many companies have made efforts to black out their satellites, they continue to launch at breakneck speed.
“We must not make progress at any cost,” said Dr Dreglon-Reid. “It’s like building a brand new development on a historic site. You can’t just do that. You have to preserve these things.”
He also acknowledged that astronomers do not own the night sky but are interested in preserving it.
“What we want to do is share the night sky and get the public to understand that this is a potential problem,” he said.