The Milky Way Galaxy is moving at about 600 km/s relative to the cosmic microwave background radiation. Why?
A) The Milky Way is being gravitationally attracted by several nearby superclusters of galaxies.
B) This speed is the orbital speed of the Local Group of galaxies around the Virgo cluster.
C) There is no particular reason. All galaxies have "small" random speeds in addition to the universal expansion, and 600 km/s is the speed of the Milky Way.
D) This speed is the orbital speed of the Milky Way Galaxy around the Andromeda Galaxy.

Question

Quizplus · Accepted Answer

The Milky Way's motion at about 600 km/s relative to the cosmic microwave background radiation is primarily due to gravitational attraction from nearby superclusters of galaxies, including the Great Attractor, which influences the motion of galaxies in our local part of the universe.

The Milky Way Galaxy Is Moving at About 600 Km/s