“It’s the first meaningful estimate of when cosmic dawn occurred because it’s based on a sizeable population of galaxies.” “If we’d have measured the age of one galaxy, sceptics would have said that maybe it’s a special galaxy, but we have six,” says Ellis. Those distant stars are some of the very first stars that ever formed, so their ages tell us the date of cosmic dawn, which the researchers calculated to be around 13.5 billion years ago. The researchers observed these six galaxies with four of the most powerful telescopes on Earth to measure their distances as precisely as possible and determine how old the stars in the galaxies are. Read more: We’ve found the oldest ever galaxy that looks like our own
