Alessandro Marconi

The red dot in the James Webb Space Telescope image is the galaxy Bz5.3, whose light has traveled 12.5 billion years to reach us. It lies behind the Bullet Cluster, whose gravitational field acted as a lens and brightened it by a factor of 3.7.

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.

400 million years after the Big Bang, the James Webb Space Telescope noticed a bright spot near the galaxy GN-z11 — like a distant lighthouse whose light pushed through the primordial darkness.

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…