Sky watchers in Britain have spotted something very strange in recent nights – a train of stars moving in a line across the night sky.
The “chain” of lights are actually tiny satellites launched by Elon Musk and should be visible for the rest of the week, according to space experts.
Reports of sightings were spread across the UK, with users in London, Manchester and Leeds among those on social media claiming to have seen the craft.
Clear skies and the position of the satellites should ensure they are visible for the next five or so days, space experts said.
SpaceX launched a batch of 60 small satellites into low-Earth orbit in March for Musk's new Starlink internet service.
In total, 300 have been launched so far, with 12,000 planned in the long run.
Musk hopes the Starlink satellites will generate cash for his larger ambitions in space.
The satellites have become easily visible from the UK in recent days, with apps allowing stargazers to work out when they will be visible.
Sophie Allan, of the National Space Centre, said that the satellites are visible due to their low orbit and their angle to the sun – plus clear night skies over Britain.
The National Space Centre wrote in a blog post: “Many people have been asking about a string of bright lights heading over their houses late at night.
“If you have seen this series of bright objects in the night sky, it is most likely that you have seen the SpaceX Starlink Satellites.
“The satellites are launched in batches of 60 deploying into an orbit about 180 miles above our planet, before thruster firings over the next one to four months move them to an operational altitude of around 340 miles.”
The satellites form the initial phase of a planned constellation capable of beaming signals for high-speed internet service from space to paying customers around the globe.
Musk has said he sees the new Starlink venture as an important new revenue stream for his California-based Space Exploration Technologies, or SpaceX.
Tech billionaire Musk said last year: “We think this is a key stepping stone on the way toward establishing a self-sustaining city on Mars and a base on the moon."