Multiple choice general knowledge science & technology If something is hurtling towards us at 0.9c (90% speed of light) it exhibits Blue Shift Red Shift Green Shift Dangling Reveal answer Fill a bubble to check yourself A Correct answer Explanation According to the Doppler effect, when a source moves toward an observer, light waves are compressed (shorter wavelength), causing a blueshift. At 0.9c, this relativistic blueshift would be dramatic.