UCLA astrophysicist Erik Petigura studied four baby planets in the V1298 Tau system that are becoming super-Earths and sub-Neptunes. Despite being 5 to 10 times Earth’s radius, the planets have masses only 5 to 15 times Earth’s, meaning they are about as dense as Styrofoam. ucla.in/4aPC8Kz 🧪🔭