If you think you've met the wildest exoplanet yet, you haven't learned about TOI-4507 b.
This strange world, which sits about 578 light-years from the solar system, breaks almost every known rule for how planets should behave. First off, it orbits a very young star that's just 700 million years old, making it one of the youngest planetary systems ever discovered. The planet is 9x wider than Earth, but only 30 times its mass. That means it's as wide as Jupiter but less than a tenth of its mass, a very light planet. This odd combination of large size and small mass classifies TOI-4507 b as a "super-puff" — an exoplanet with a large, extended atmosphere.
