Using one of the most powerful telescopes on Earth, astronomers have witnessed an intimidating 2-million-mile-per-hour (3.2-million-kilometer-per-hour) smash-up between galaxies at a dangerous "cosmic crossroads," the site of multiple previous collisions.
The collision occurred when the galaxy NGC 7318b ripped through the site of previous galactic smash-ups, a galactic grouping called "Stephan's Quintet." The impact created a powerful shockwave in this complex field of cosmic debris that "reawakened" the quintet.
