Clearly visible in this radio image of M84 are two jets and two lobes, analogous to those of galaxy M87. The jets are thin streams emanating from the galaxy’s center, while the lobes are the fainter, diffuse blobs at the ends of the jets. Because of these features astronomers have classified M84 as a weak radio galaxy 
    The shape of the jets and lobes tells M84’s history: the jets’ curves are thought to be caused by the swift movement of the galaxy through the intergalactic gas of the Virgo Cluster. The intergalactic gas slows the outer parts of M84’s jets, causing them to lag behind those portions nearer the galaxy’s center. Like a cloud exhaled by a smoker and encountering air in a room, the jets slow and assume a more or