Coronal Mass Ejection
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Basic Information

A Coronal Mass Ejection is a huge blast or wave of plasma ejected from a star. The plasma is mostly made of loose electrons and protons. CMEs travel at extremely high speeds, and cause significant devastation to nearby planets they pass over/through. Planets with a strong magnetic field (like The Earth) will deflect most of the CME, and experience lesser effects. Planets with weaker fields (like Mars) take the full brunt of it. One reason Mars has so little atmosphere is that frequent CMEs blow the air right off the planet.

On earth, most CMEs do very little harm to us. A big CME, however, could have a significant impact. The last big one, in 1859 (the September 1859 Geomagnetic Storm) caused visible auroras as far south as Rome, and caused trouble for the telegraph system. Such a big one hitting today would have an effect on our communications network and power grid similar to the Electro Magnetic Pulse of a nuclear bomb. Anyone flying in an airplane over the north or south pole at the time would be irradiated with the force of a thousand chest x-rays. It could knock satellites out of orbit, and turn power-lines into wildfires. The Space Environment Center of the NOOA monitors for such CME activity, but given the speed CMEs travel at (taking from 16 hours to a few days to reach the earth), there's not a lot of warning.

Thankfully, the majority of CME's are not pointed at the Earth, and instead shoot off in other directions from the Sun.


1. TV Show: The Universe on the History Channel

Game and Story Use

  • A really big CME is a Disaster that could knock mankind back to the stone age - temporarily. The immediate death toll would be minimal, but our infrastructure would be torn asunder and take a long time to rebuild.
    • Some governments might not recover, so After The Big CME is pretty close to After The End.
    • This would change the timelines described for Post-Apocalyptic Decay, by adding fires and wrecking machinery.
    • It wouldn't directly kill all that many people on its own, so if you're looking for a way to depopulate your setting, you'll need to have something else horrible happen at around the same time. If this happened in the middle of some other sort of apocalyptic event, it would undermine world response, and compound the dangers and impact.
  • A spacecraft traveling anywhere near the sun would be especially vulnerable to CME dangers.
  • Other stars are likely to have similar phenomenon. This might be a hazard in any planetary system.
  • A CME-causing WMD would be an epic opening salvo to a invasion from outerspace. Park your fleet on one side of the sun, somehow trigger and direct a coronal discharge in the opposite direction, then swoop in to invade just a few days (or months, depending on your stardrive) later when the world is still reeling from the recent loss of their technology.
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