A new satellite outshines some of the brightest stars in the sky

Last November, a low-Earth orbit satellite blasted into a spacious array spanning about 700 square feet, about the size of a studio apartment.

The BlueWalker 3 satellite has since become one of the brightest objects in the sky, outshining some of the brightest stars in the Milky Way, according to Study published Monday In the wild, it’s just the first of dozens of similar satellites being developed by AST SpaceMobile, a company that aims to keep smartphones connected from orbit.

Astronomers were already concerned about the emergence of massive constellations of satellites, such as SpaceX’s Starlink, that feature bright surfaces that sometimes interfere with the view of space from Earth. The launch and deployment of BlueWalker 3 has exacerbated these concerns.

“It’s not necessarily that it’s one satellite, but that it’s a progenitor or prototype of a constellation, so there’s going to be a lot of those out there eventually,” said Siegfried Eagle, an astrophysicist at the University of Illinois at Urbana-Champaign and author of the new study.

Initially launched in September 2022, BlueWalker 3 is the flagship of AST SpaceMobile’s BlueBird satellites, which are intended to serve as a network of orbiting cell towers with the goal of “democratizing access to knowledge and information no matter where people live and work.” A company spokesman said. He told AST SpaceMobile. Last month, BlueWalker 3 was successfully launched It transmitted its first 5G connection To a smartphone in the cell coverage gap on Earth.

AST SpaceMobile is one of many companies racing to meet the growing demand for global broadband connectivity. SpaceX has launched about 5,000 satellites into space as part of its Starlink network, which already provides satellite internet service. For customers around the world. And other companies, such as Amazon (which is set to… The first satellite prototype was launched on Friday) and OneWeb, have similar ambitions, and many countries are developing their own mega telecom clusters.

“Right now, there are 18 constellations that we know of that are planned around the world,” Dr. Eagle said. “The total number of satellites is a staggering half a million people are planning to put there. That’s 100 times more than we already have.”

The rapid proliferation of satellites in recent years has alarmed stargazers from all walks of life. When 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 that may be visible to the naked eye.

“There will be a big change in these constellations,” said Jeremy Tregloan-Reid, an astronomer at the University of Atacama in Chile and author of the study.

AST SpaceMobile made the BlueWalker 3 array very large in order to beam powerful cellular coverage directly to phones on the ground. The satellite consists of many small antennas that can connect existing smartphones, an approach that distinguishes the company from Starlink and other planned towers that currently rely on ground antennas or dishes.

To find 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 revealed that BlueWalker 3 had reached a size that made it as bright as Procyon and Achernar, two of the 10 brightest stars in the sky, according to the study.

“I really like how they used so many different telescopes from so many different places in the world; it sheds light,” said Samantha Lawler, an astronomer at the University of Regina in Saskatchewan, who was not involved in the study but wrote an accompanying Nature article. “On how this is a truly global problem.” “One country, or one small company, launches a satellite and it can be seen everywhere in the world.”

AST SpaceMobile said it is working with astronomers on techniques to reduce turbulence. It also compared the number in its group to the tens of thousands planned by other companies. The spokesman said it could “provide significant global coverage with about 90 satellites.”

Although the number of BlueBird satellites will be much fewer, they are at least 64 times larger than a Starlink satellite and much brighter. SpaceX orbiters are also brighter in the days after deployment, but become dimmer once they settle into their target orbits.

Astronomers expect the Bluebird moons to remain bright in the sky for most of their lives. As a result, one of these satellites could interfere with data captured by astronomical observatories.

“It is so bright that it would destroy entire images recorded with wide-field telescopes, such as the Vera Rubin Observatory, for example,” Dr. Eagle said.

There are currently no regulations preventing companies from launching bright, massive constellations of satellites, although many scientists and dark-sky advocates, including indigenous rights groups, are defending the rules. Even as many companies make efforts to darken their satellites, they continue to launch them at a dizzying pace.

“We should not make progress at any cost,” Dr. Tregloan-Reid said. “It’s like building a completely new project on a historic site. You can’t just do that. You have to protect these things.”

He also acknowledged that astronomers do not own the night sky but have an interest in preserving it.

“What we would like to do is share the night sky and make the public understand that this is a potential problem,” he said.