Harley Katz

A boiling cauldron: steam rises, water churns, and the temperature varies from point to point. So it is in space: the gas clouds around young stars are not smooth spheres but a seething mixture with vortices and density fluctuations. Astronomers long treated such clouds as homogeneous, but this simplification can skew conclusions.

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.

If you turn on a lamp in a room, it illuminates the walls. But if you place the same lamp in a vast hall, the light barely reaches the corners. Similarly, radiation from young stars affects gas in a galaxy: it knocks electrons out of hydrogen atoms, making the gas glow.

When the James Webb Space Telescope turned its gaze deep into time, astronomers expected to see familiar galaxies. Instead, the images were dotted with a scattering of bright, incredibly compact red dots.

When JWST peered into the young universe at redshifts of 6–10, it revealed a scattering of mysterious 'little red dots' (LRDs). These objects combined features of galaxies and active nuclei, but their spectra refused to fit into familiar patterns.