The James Webb Space Telescope has detected a key building block of life at the dawn of the universe, upending what we know about the first galaxies.
Astronomers classify elements heavier than hydrogen and helium as metals. That's because, aside from hydrogen and trace amounts of lithium, these elements were forged inside the fiery furnaces of stars and distributed throughout the universe by star explosions called supernovas. Related: James Webb telescope discovers earliest galaxy in the known universe — and its shockingly big