Prototype Satellite AST SpaceMobile Raises Concerns about Brightness and Potential Impact on Astronomy

A prototype satellite launched by AST SpaceMobile has been causing concerns among astronomers due to its brightness in the night sky. The satellite, BlueWalker 3, was launched into low Earth orbit in September 2022 and deployed a large antenna to support direct-to-device communications.

Astronomers around the world observed BlueWalker 3 and documented its brightness in an upcoming paper to be published in the journal Nature. Shortly after the antenna deployment, the satellite’s magnitude increased from 6 to 0.4, making it one of the brightest objects in the night sky. Although the brightness fluctuated over time, reaching magnitude 0.4 again in April 2023, astronomers remain worried about the increasing brightness of commercial satellites and the impact it will have on astronomy.

Siegfried Eggl of the University of Illinois at Urbana-Champaign, one of the authors of the study, expressed concerns about the trend of larger and brighter commercial satellites being launched in the future. The International Astronomical Union Centre for the Protection of the Dark and Quiet Sky from Satellite Constellation Interference (IAU CPS) is working to study the impact of satellite constellations on astronomy and develop methods to mitigate those effects.

AST SpaceMobile has stated that they are collaborating with NASA and astronomy working groups to find solutions to the concerns raised. They plan to reduce satellite brightness through “roll-tilting flight maneuvers” and the use of anti-reflective materials in future satellites.

While AST SpaceMobile’s satellite constellation is smaller compared to others, with approximately 90 satellites needed for global coverage, concerns about brightness and interference with radio astronomy remain. SpaceX has worked with astronomers to address the brightness of its Starlink satellites and has coordination agreements with the National Science Foundation (NSF). The NSF is also finalizing similar agreements with Amazon and OneWeb. However, no coordination agreement has been announced between the NSF and AST SpaceMobile.

Despite concerns, astronomers understand the need for improved connectivity and internet access but emphasize the importance of balancing progress with the negative impact of bright satellites on the night sky.

Source: Not provided.