Pen-Elayne on the Web

Didn't We Just Go Through One of Those?

Via Susie Madrak this time: looks like we're in for yet another major solar flare, the biggest since 1989 and the third largest on record. Due to hit on Thursday, possibly causing a major geomagnetic storm. The NY Times evokes 1859 and also explains why last Friday's storm turned out so relatively minimal:

But only when the speeding plasma has an intense magnetic field that is opposite to Earth's... does it cause a powerful magnetic storm. And scientists can measure a storm's magnetic field only about 30 minutes in advance.

The space storm that careered toward Earth last Friday, for example, was traveling in the right direction, at a high speed, and with a somewhat intense magnetic field — three of the criteria — alarming scientists as they watched it approach for two days. But the direction of its magnetic field was not opposite to Earth's, so it had only a small impact...

So in other words, we won't know what kind of havoc it may cause until about a half hour before it reaches us. Swell.