Not only do we find hydrogen between the stars, but also a variety of interesting complex molecules which also emit radio energy at specific wavelengths. These molecules are found in regions that are appropriately known as molecular clouds. . The National Radio Astronomy Observatory keeps track of these molecules which include something as simple as carbon dioxide to molecules with more than a dozen atoms. One of the nearest important molecular clouds can be found in the constellation of Orion, a busy place for star formation.But there is more than just gas between the stars. We find an appreciable amount of dust. This dust has a noticeable effect on starlight.