 Here we see a pair of barred spiral galaxies that have just begun a merge. Though their nuclei are still separated by a large distance, the shapes of the galaxies are significantly distorted. For example, a galaxy on the left contains very pronounced tidal tails—long extended ribbons of gas, dust, and stars. The bright blue areas are stellar nurseries. These vigorous bursts are triggered by the massive gravitational interactions which stir up interstellar gas and dust out of which new stars are created. The galaxies in this system will continue their merger for millions of years before finally becoming a single galaxy.