On Earth, water vapor condenses into droplets that fall as rain. On Jupiter, helium condenses as mist 6,000 miles below the planet's cloud tops, then forms helium "rain." Scientists at the University of California, Berkeley say the helium doesn't rise as it does on Earth. The drops fall through a fluid atmosphere of metallic hydrogen toward the planet's core of rock and ice. At 62,000 miles below the cloud tops, temperatures reach 5,000 degrees C., with pressures 1 million to 2 million times Earth's. Nasty.