Companies' plans for satellite constellations 'put night sky at risk'

Schemes from firms such as Elon Musk's SpaceX raise fears for our view of heavens

The spectacular view of the heavens on a clear, dark night is under threat from plans to launch tens of thousands of satellites that will be visible tearing across the sky, astronomers have been told.

Tech firms have begun to place a number of satellite "mega constellations" into low Earth orbit in a move designed to expand internet access and open new markets in the developing world.