Jupiter may look like a giant ball of hydrogen and helium—but its insides tell a far more dramatic story. Thanks to NASA’s Juno mission, scientists have discovered that Jupiter holds up to 30 Earth-masses of heavy elements buried deep inside. And they’re not spread out evenly—they’re clumped near the core, shaking up everything we thought we knew about how gas giants form. Instead of growing slowly by collecting space dust and pebbles, Jupiter likely feasted on massive rocky planetesimals—the very building blocks of planets—before gulping down gas from the solar nebula. These weren’t just snacks… they were entire baby planets. And there’s more: the unexpected distribution of metals suggests that Jupiter’s interior isn’t churning like boiling water as once believed. That changes how we model giant planets—not just in our Solar System, but across the galaxy. With telescopes like James Webb peering at distant worlds, this discovery could mean we’ve been underestimating what exoplanets are really made of. Jupiter isn’t just a planet—it’s a cosmic time capsule. 📄 Source: Y. Miguel et al., “Jupiter’s Inhomogeneous Envelope,” A&A (2022)