Milky Way Molecule Map . ... Columbia 1.2-m Radio Telescopes Explanation: Where are the Milky Way's gas clouds and where are they going? Stars form in gas clouds , and the motion of gas clouds tell us about the size and rotation speed of our own Milky Way Galaxy . ... Fortunately, at least small amounts of heavier gases co-exist, one of them being carbon monoxide (CO), which is relatively easy to detect at radio wavelengths. ... The band of our Milky Way Galaxy spans the middle. ...