Bluewalker 3 satellite is brighter than 99.8 per cent of visible stars

Observations of a huge test satellite that launched in September have fuelled concerns about the impact a planned fleet could have on astronomy

By Alex Wilkins

A test satellite for a future space-to-Earth mobile phone network is brighter than 99.8 per cent of stars visible to the naked eye. If a planned fleet of 100 additional satellites is as bright or brighter, astronomers are concerned it could severely impact ground-based astronomy.

In September, Texas-based firm AST SpaceMobile launched its BlueWalker 3 satellite to test beaming a cellular connection directly to mobile phones from space.

But astronomers were concerned that the test …