(BBC NEWS) Astronomers are warning that their view of the Universe could be under threat.
From next week, a campaign to launch thousands of new satellites will begin in earnest, offering high-speed internet access from space.
But the first fleets of these spacecraft, which have already been sent into orbit by US company SpaceX, are affecting images of the night sky.
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They are appearing as bright white streaks, so dazzling that they are competing with the stars.