In astronomy, the interstellar medium (ISM) is the matter and radiation that exist in the space between the star systems in a galaxy. This matter includes gas in ionic, atomic, and molecular form, as well as dust and cosmic rays. It fills interstellar space and blends smoothly into the surrounding intergalactic space
To make a cake you could use a standardized recipe vanilla cake recipe. by doing this you can add just about anything you wanted by making minimal changes to the base recipe.
