One of the brightest objects in the night sky is a man-made satellite

The prototype satellite has become one of the brightest objects in the night sky, and it may soon be accompanied by dozens of others. that Tracking of the BlueWalker 3 satellite, launched by AST SpaceMobile in September 2022, has found that it is at times brighter than all but a few stars and planets visible from Earth. Results published in the journal nature It highlights rapidly mounting concern among astronomers, who warn that the influx of private space projects in low Earth orbit could alter our view of the night sky and interfere with research.

Researchers at the International Astronomical Union Center for the Protection of Dark and Quiet Skies from Constellation Satellite (CPS) interference monitored BlueWalker 3 over a period of 130 days. The BlueWalker 3 antenna array is approximately 700 square feet, making it the largest yet for a commercial low-Earth orbit satellite. This huge group reflects sunlight, and after it blooms, its brightness increases. The effect is not constant, but fluctuates depending on factors such as the satellite’s position relative to the sun, and viewing angle. The CPS team has observed them from locations in Chile, the United States, Mexico, New Zealand, the Netherlands and Morocco.

“These results show a continuing trend toward larger and brighter commercial satellites, which is particularly concerning given plans to launch more satellites in the coming years,” he said. Siegfried Eagle, one of the study’s co-authors. “Although these satellites can play a role in improving communications, it is necessary to minimize disruption to scientific observations.” AST SpaceMobile eventually plans to deploy a fleet of approximately 100 cellular broadband satellites based on the BlueWalker 3 design.

SpaceX, whose thousands of Starlink satellites have repeatedly come under scrutiny for their potential impact on the night sky, has experimented with dark coatings to reduce the amount of reflected light, with limited success. For astronomers, who are increasingly a headache, It’s not enough. The researchers noted in their paper that Earth observation stations will need to develop satellite avoidance strategies to overcome these artificial constellations.

Visibility is not the only problem. Commercial satellites, including BlueWalker 3, flooding low-Earth orbit also threaten to interfere with radio astronomy. separate Published earlier this year it found that Starlink satellites were leaking “unintended electromagnetic radiation” that could disrupt radio telescope observations.