Is not this a nice and dynamic picture? NASA and ESA published it on May 1
… shows all signs that she was involved in an accident involving an immediate galaxy. Instead of destroying the galaxy, the chance encounter brings forth a new generation of stars and presumably planets.
The right side of the galaxy is illuminated by star formation, which is reflected in the abundance of young blue stars and star-incubating pink fog. The left side, however, looks intact. It contains clues to the galaxy's earlier spiral structure, which was in a normal galactic evolution at some point in time.
The larger offender galaxy, NGC 4490, is at the bottom of the frame. The two galaxies annihilated each other millions of years ago and are now 24,000 light-years apart. The gravitational tug-of-war between them produced rippling patches of gas and dust of higher density in both galaxies. This activity triggered a wave of star formation.
This galaxy is a close example of the cosmic bumper activity that occurred more frequently billions of years ago, when the universe was smaller and the galaxies were closer together.
NGC 4485 is 25 million light-years away in the northern constellation Canes Venatici (the hounds).
Conclusion: Hubble Space Telescope image of the galaxy NGC 4490, wiped sideways by another galaxy and undergoing rampant star formation … but only on one side.