The Milky Way and Andromeda are on a Collision Course (it will take a few billion years..). From the persepective of Earth, the approaching Andromeda must have a _____ effect.

Question

a
Redshift
b
Blueshift
c
Elliptical
d
Galactic

Answer 1

From the perspective of Earth, the approaching Andromeda galaxy must have a b. Blueshift effect.

A blueshift occurs when an object is moving toward the observer, causing the wavelengths of light to shorten. In this case, since Andromeda is approaching the Milky Way, its light will be shifted toward the blue end of the spectrum.