One of the biggest mysteries in astrophysics is how supermassive black holes form in the early Universe and grow to be SO supermassive.
There's a limit to how fast they can grow in mass, so they shouldn't exist so early in the Universe's history.
Yet the James Webb Space Telescope (JWST) and the Chandra X-ray
observatory have together just found the most distant supermassive black hole known (at a redshift of z=10.3, meaning the Universe was just 450 million years old when the light left that galaxy).
The best estimate we have of the black hole's mass puts it at about the same mass as it's galaxy!
Suggesting that perhaps the black hole formed FIRST as direct collapse black hole and then the galaxy of stars formed around it... essentially solving the astrophysics equivalent of: "what came first the chicken or the egg?"