 Interstellar clouds like the Orion Nebula are found throughout galaxies such as the Milky Way . They begin as gravitationally bound blobs of cold , neutral hydrogen , intermixed with traces of other elements . The cloud can contain hundreds of thousands of solar masses and extend for hundreds of light years . The tiny force of gravity that could compel the cloud to collapse is counterbalanced by the very faint pressure of the gas in the cloud . 
