How long does it take a coronal mass ejection to affect radio propagation on Earth?
28 days
14 days
4 to 8 minutes
15 hours to several days✓Correct answer
Explanation
A coronal mass ejection is a cloud of plasma, not light, so it crosses the Sun-Earth distance at solar wind speeds of a few hundred to a couple of thousand km per second. That gives an arrival time of about 15 hours for the fastest events and up to several days for slow ones.