A one-in-a-million supernova seen five times could reveal the Universe’s true speed

A spectacular cosmic event nicknamed “SN Winny” could help solve one of astronomy’s biggest mysteries: how fast the universe is expanding. This rare superluminous supernova, located 10 billion light-years away, appears five times in the sky thanks to gravitational lensing, creating a dazzling “cosmic fireworks” effect. By measuring the slight delays between each appearance—caused by light taking different paths around two foreground galaxies—scientists can directly calculate the universe’s expansion rate.