Molekülwolken, or molecular clouds, are large regions in space filled with gas and dust. They are primarily composed of hydrogen molecules, along with other elements like helium and carbon. These clouds are cold and dense, making them the perfect environment for star formation. These clouds can span several light-years and are often found in areas of active star formation, such as Orion Nebula. The gravitational forces within Molekülwolken can cause the gas and dust to clump together, eventually leading to the birth of new stars and planetary systems.