Coronal Mass Ejections

A coronal mass ejection and prominence eruption observed in white light from the SMM (Solar Maximum Mission) spacecraft. The time of each panel increases from left to right. The dashed inner circle in each panel is the solar radius, the occulting radius is at 1.6 solar radii. Click on image for full size (125K JPEG) Courtesy of the High Altitude Observatory

These catastrophic events that the author is speaking about are coronal mass ejections (CME's).

Coronal mass ejections are explosions in the Sun's corona that spew out solar particles. A lot of material is thrown out into the solar wind. Coronal mass ejections can be dangerous when they hit the Earth.

CME's can seriously disrupt the Earth's environment. Intense radiation from the Sun, which arrives only 8 minutes after being released, can alter the Earth's outer atmosphere, disrupting long-distance radio communications. Very energetic particles pushed along by the shock wave of the CME can endanger astronauts or fry satellite electronics. These energetic particles arrive at the Earth (or Moon) about an hour later. The actual coronal mass ejection arrives at the Earth one to four days after the initial eruption, resulting in strong geomagnetic storms, aurorae and electrical power blackouts.

Coronal mass ejections will become more and more frequent as we near solar maximum. CME's, not discovered until the 1970's, are difficult to detect. That is why we need satellites such as the ACE satellite which acts as a spaceweather station while in orbit. ACE can provide a one-hour advance warning of any geomagnetic storms that would affect the Earth.