Across the galaxy, the most common type of planet is one our solar system has never produced — a world larger than Earth but smaller than Neptune, catalogued now in the thousands among distant stars. Our eight planets skip this size range entirely, leaping from rocky Earth to gaseous Neptune with nothing in between. This absence, once invisible because we had no other systems to compare, has become one of the more humbling revelations of the exoplanet era: the solar system is not the template for planetary life, but a rare and perhaps peculiar exception to it.