interstellar-dust

The interstellar medium (ISM), the gas and dust filling the space between stars, is not empty. It is a multiphase medium ranging from 10 K molecular clouds where stars form to million-kelvin plasma heated by supernovae. Dust hides the centre of our galaxy from visible light, and the ISM is both the raw material for new stars and the place where dying stars deposit their products.

Interstellar dust grains, typically far thinner than a human hair, dim starlight, build molecular hydrogen, shield star-forming clouds, carry the isotopic signatures of dead stars, and supply the solids from which planets grow.