Part of the problem is that extreme solar storms (also called coronal mass ejections) are relatively rare; scientists estimate the probability of an extreme space weather directly impacting Earth to be between 1.6% to 12% per decade, according to Abdu Jyothi’s paper.

What are the chances of a coronal mass ejection?

The frequency of ejections depends on the phase of the solar cycle: from about 0.2 per day near the solar minimum to 3.5 per day near the solar maximum.

How long does it take a coronal mass ejection to reach Earth?

CMEs travel outward from the Sun at speeds ranging from slower than 250 kilometers per second (km/s) to as fast as near 3000 km/s. The fastest Earth-directed CMEs can reach our planet in as little as 15-18 hours. Slower CMEs can take several days to arrive.