JWST spotted sulfur in the atmospheres of massive gas giants orbiting HR 8799, revealing they likely formed through core accretion rather than star-like collapse. Even planets up to ten times Jupiter’s mass may grow the same way Jupiter did — just on a much grander scale. Credit: Jean-Baptiste Ruffio Gas giants are enormous planets made primarily of hydrogen and helium. They may contain dense central cores, but unlike Earth, they do not have solid surfaces you could stand on. In our solar