We all know that feeling of looking up at a silver-flaked night sky with a mixture of wonder and mild confusion: is that Jupiter or Venus? A shooting star or one of Elon Musk’s satellites? And, didn’t the Southern Cross previously have a fifth star?

“The fifth star used to be clearly visible,” says astronomer Nick Lomb. “Now you can hardly see it. When I was young, you could still get some idea of the Milky Way from the city, but now there is no hope.”