Remember that line in my five stages of exam preparation, “I’ll start studying in earnest RIGHT NOW, if you’ll just… what? There’s a tsunami warning for Fiji?” Well, this is the equivalent of that, except in space:

A violent solar explosion sent a dangerous wave of radiation through space late Tuesday, prompting NASA to order the crews of Discovery and the International Space Station to take shelter overnight.

The solar flare erupted around 9:40 p.m., unleashing enough radiation to disrupt radio communications on Earth and in orbit while endangering astronauts circling 220 miles above the planet.

NASA flight surgeons and agency radiation experts determined that the burst of highly energetic particles approached a limit that made preventative action prudent.

Station commander Michael Lopez-Alegria and shuttle skipper Mark Polansky were told to move their crews to the most shielded areas in either spacecraft.

SpaceWeather.com has details on the flare and storm:

Sunspot 930 has just unleashed another big solar flare, an X3-class explosion at 0240 UT on Dec. 13th. … As a result of the blast, a radiation storm is underway. Based on the energy and number of solar protons streaming past Earth, NOAA ranks the storm as category S2: satellites may experience some glitches and reboots, but astronauts are in no danger.

No danger, but it’s still good to be prudent, I guess. If the radiation storm were to reach S3 levels (like the one last week did), then the astronauts would potentially be in some danger. But the Proton Flux chart indicates that the storm is weakening, not strengthening, so that’s good news.

Space.com has more on the flare/storm, including the observation: “Such storms are fairly common when the Sun is at its most active, but they are rare during the current low point in the 11-year cycle of solar activity.”

Anyway, SpaceWeather.com adds:

The explosion hurled a coronal mass ejection toward Earth. (Confirmed by SOHO; stay tuned for the movie.) Sky watchers should be alert for auroras when it arrives on Dec. 14th.

Hmm… I assume that means the evening of the 14th. Wouldn’t it be nice, though, if this was a particularly fast-moving CME, and it got here in time for the peak of the Geminid meteor shower overnight tonight and into the wee hours of tomorrow morning (the 14th)? Meteors + auroras = space-nerd heaven!

P.S. More on the Geminids here.