WASHINGTON – A prototype satellite known as BlueWalker 3 has riled the scientific community which declared this week that it, a man-made piece of communications equipment, is now one of the brightest objects visible in the night sky.
Causing further concern is the company that launched the satellite, AST SpaceMobile, envisions having 90 more in the sky as part of an ambitious 5G communications system it is developing.
“It is unacceptably bright for many sky observers around the world,” Meredith Rawls, co-author of a paper on the finding and member of the IAU Center for the Protection of the Dark and Quiet Sky from Satellite Constellation Interference, told Space.com.
The reason BlueWalker 3 appears so bright to the naked eye is because it possesses a massive structure known as a phased-array antenna -- the largest commercial antenna system ever deployed to low-Earth orbit. BlueWalker 3 was launched in September 2022.
That array takes up about 690 square feet of space — and because those panels are reflective, it’s almost like BlueWalker 3 is a giant mirror continuously bouncing sunlight toward our eyes.
“The satellite would be ranging among the top 10 brightest objects if you count the stars and the sun. It’s just incredible,” Siegfried Eggl, another co-author of the study and aerospace engineer at the University of Illinois Urbana-Champaign, told The Washington Post. “It’s a byproduct, I think, of the fact that these environmental considerations are generally not done.”
An AST spokesperson told Space.com it envisions about 90 similar satellites roaming the skies to make what experts call a “satellite constellation.” That stands in contrast to other such constellations that are expected to require thousands of satellites to achieve their coverage goals.
“We are building the first and only space-based cellular broadband network designed to seamlessly connect everyday smartphones,” the AST spokesperson told Space.com. “By connecting people, we aim to alleviate poverty, spur economic development, foster a diverse digital society and save lives.”
The extra light has several implications for astronomers but also nonscientists.
The light interferes with data collection. For instance, streaks of satellites could mask objects in the vicinity of Earth — like an asteroid, Eggl said. A previous study by Eggl showed that a portion of near-Earth objects could be affected by these streaks in data.
Light pollution also affects people’s circadian rhythms and migratory patterns for other animals.
The ultrabright satellite prototype also has sparked concerns about whether our night sky is being littered with far too many artificial stars — especially because it’s not an isolated situation, Space.com said. SpaceX’s Starlink satellites, for instance, have already spurred a similar discussion.
“This satellite was launched without much consideration of its impact on astronomy,” Eggl told Space.com. “The IAU CPS seeks to change that and work on solutions together with the space industry.”