Found roughly 50 million light-years from Earth in the constellation of Ursa Major, this is NGC 3310: a spiral galaxy with a turbulent past. Around 100 million years back, it violently clashed with one of its neighbors, inciting a chain reaction that culminated in a burst of star formation activity taking place within its borders.
This burst was triggered by something called density waves, which propagate when a change in gravity compresses the galaxy’s gas supply, causing sections to collapse. This Hubble-composite showcases generations of stars that came before and after the merger, revealing that the young outnumber the old (some are so young, in fact, that astronomers now think the aftereffects of a merger linger longer than we previously suspected).
All in all, NGC 3310 spans approximately 50,000 light-years across, which makes it only half the size of the Milky Way (though by some estimates, it may be much smaller than that, perhaps just 22,000 light-years across).