Elias 2-24 b is young enough that astronomers are seeing it before its planetary neighborhood has finished taking shape. Yet the planet is already roughly Jupiter-sized. It orbits about 55 times the Earth-Sun distance, far out in a disk where assembling such a massive world should be difficult and slow. That mismatch is what makes the discovery so intriguing: astronomers are not looking at an old planet and guessing how it formed. They may be watching a giant world grow in real time.