The large face-on grand design spiral galaxy NGC 1232 has undoubtedly interacted in complex ways with its smaller irregular companion galaxy NGC 1232A (seen in the image on the left) and that interaction has left an indelible mark on the larger galaxy. The sweeping spiral arms appear to be "bent" in areas rather than the gently curving structures seen in undisturbed spiral galaxies. This aberration of the arms is likely due to gravitational encounters with NGC 1232A as it orbits the larger spiral. Radiowave studies indicate a large envelope of neutral gas extending well beyond the optical extent of the galaxy. Rotational velocity measurements of the galaxies huge spiral arms suggest a large component of dark matter comprising NGC 1232. NGC1232 spans some 200,000 light years making it almost twice the size of the Milky Way.