Add Yahoo as a preferred source to see more of our stories on Google. An illustration of a star slowly evaporating an orbiting planet's atmosphere. Helium could make up almost half the mass of the ...

Every gas giant astronomers have ever studied shares a basic recipe: a thick envelope of hydrogen and helium, with heavier elements sprinkled in as trace ingredients. A planet orbiting a rapidly ...

Two geoscientists, one with Princeton University, the other with Guangzhou Institute of Geochemistry, have developed a theory to explain how helium-3 leaks from the Earth's core into the mantle. In ...