November 2, 2000: What appears as a bird's head, leaning over to snatch up a tasty meal, is a striking example of a galaxy collision in NGC 6745. The "bird" is a large spiral galaxy, with its core still intact. It is peering at its "prey," a smaller passing galaxy (nearly out of the field of view at lower right). The bright blue beak and bright, whitish-blue top feathers show the distinct path taken during the smaller galaxy's journey. These galaxies did not merely interact gravitationally as they passed one another; they actually collided.
When galaxies collide, the stars that are part of each galaxy will almost never collide. They usually pass freely between each other with little damage. That's because the stars are far apart from each other.
But the vast clouds of gas and dust between the stars do smash into each other. These collisions compress the clouds and trigger new star birth. The hot blue stars in this image are evidence of this star formation.