Filippo Mannucci

Light from distant galaxies carries a hidden recipe — a color barcode revealing the elements inside. For decades, astronomers used familiar tricks to decode it, but the James Webb Space Telescope shows these tricks fail for the earliest galaxies.

Light from a distant quasar, the bright core of a galaxy, passes by a massive galaxy and bends, like a flashlight beam through uneven glass. If the lens and source align almost perfectly, we see not one quasar but several copies.

Two hundred forty-two thousand three hundred twenty-seven galaxies — like grains of sand on a beach. But astronomers turned this chaos into a map: the UMAP algorithm (a machine learning method) took from each galaxy eleven parameters — seven colors from optical to mid-infrared (that's photometry), magnitude…