A close-up view, with the merging galaxies circled. The red data show dust-enshrouded regions of star formation, while green and blue show carbon monoxide gas and starlight, respectively. The blue blobs outside of the circle are galaxies located much closer to us. Image: ESA/NASA/JPL-Caltech/UC Irvine/STScI/Keck/NRAO/SAO

Astronomers have caught two big ancient galaxies in the act of colliding, shedding new light on the role such megamergers played in galactic evolution during the universe’s youth.

The colossal smash up will eventually produce one giant elliptical galaxy, researchers said, suggesting that most such behemoths formed rapidly in this manner long ago, rather than growing slowly over time by gobbling up a series of relatively small galaxies.

“I think at least 90 percent of elliptical galaxies at this mass were formed through this channel,” study lead author Hai Fu, of the University of California, Irvine, told SPACE.com. [Photos of Great Galactic Crashes]

via Rare View of Ancient Galaxy Crash Revealed: Scientific American.