Brown dwarf weather, conceptual image. Computer illustration showing what the weather might look like on cool star-like bodies known as brown dwarfs. These giant balls of gas start out life like stars, but lack the mass to sustain nuclear fusion at their cores, instead cooling over time. New research suggests that most brown dwarfs are racked with colossal storms consisting of fierce winds and possibly lightning. The turbulent clouds might also rain down molten iron, hot sand or salts - materials thought to make up the cloud layers of brown dwarfs.