Collisions between galaxies
A) occur only very occasionally to produce spectacular supergalaxies containing many new stars. Only one or two examples have been detected so far.
B) are occurring all the time, all elliptical galaxies having resulted from such collisions. The collisions have cleared out all the gas and dust from these galaxies.
C) never happen since galaxies are so far apart in this universe.
D) can and do occur relatively frequently over cosmological times.

Question

Quizplus · Accepted Answer

Galaxies can and do collide relatively frequently on a cosmological timescale. These events can lead to various outcomes, including the merging of galaxies, star formation, and structural changes. The vast distances between galaxies do not preclude collisions given the immense scale and age of the universe.

Collisions Between Galaxies