NASA’s Webb Reveals Black Hole That Formed Before Its Galaxy - NASA Science (.gov)

Earth has an unusually large moon compared with other rocky planets in the solar system, but scientists still do not fully understand how it formed. A new study from researchers at the Southwest Research Institute and the University of Arizona suggests that one long-overlooked factor may have played a major role in the Moon's birth: the physical strength of the worlds that collided. Using advanced computer simulations, the researchers examined the enormous impact thought to have occurred about 4.5 billion years ago between the young Earth and a Mars-sized object. Their results reveal strikingly different outcomes depending on the temperature and structural properties of the two bodies.

The ingredients needed to build rocky planets may have appeared as early as 100 million years after the Big Bang, according to new research from the University of Portsmouth. That would place the beginnings of planet formation remarkably close to the dawn of the Universe, even before the first galaxies had fully emerged. Scientists have long thought that planets took much longer to become possible, with significant planet formation beginning several billion years into cosmic history. The new findings suggest that the necessary conditions may have developed far sooner.