In the midst of droughts, wildfires, rapidly disappearing sea ice, and El Niño, it’s easy to get caught up in weather here on Earth. But there’s a little-known weather event that could do considerably more damage. What’s worse, we’ve done little to prepare for it — and have no way to stop it. It’s called a coronal mass ejection (CME) and its effects can be disastrous.

CMEs are enormous blobs of magnetized plasma that the sun hurls from its surface anywhere from several times a day to once a week. A CME can have a billion tons of mass, pack the energy of 20 million nuclear bombs, and — if aimed in our direction — reach Earth in a matter of hours. To understand what they can do, one need only look up the Carrington event of September 1859. That’s when Earth was hit simultaneously by a CME and a solar flare, both the largest on record. FULL REPORT