Over the last week a HUGE sunspot group has been forming on the sun, and it has let out two CMEs ("coronal mass ejections"), both of which are headed toward Earth. A CME is a mass of fast moving particles which have been blasted off of the sun from a solar flare -- and the impact of those particles on our magnetic field are what cause auroras on Earth.

Well, depending on the polarity of the incoming CME, that is.

Anyway, there are three categories of flares, each with 7 sublevels: C, M and X. "C" is pretty small, "X" are most active and most disruptive to us here (can cause blackouts, electromagnetic disruptions, tv and radio jitters and all that kind of thing).

The two incoming CMEs came from an M-8 and an X-2 flare, respectively.

So, keep your eyes peeled guys, if your skies are clear. They are due to hit us on the 16th-17th, so the aurora possibilities would be for tonight and tomorrow night.

The last flare of comparative strength hit us last November, and auroras were seen clear down into Utah and California. I personally was out watching the sky then in the city, and could clearly see bright, green aurora even with city lights! (Of course I took off driving into the country to see it better, hehe...)

While I haven't seen any aurora associated with those two CMEs, it appears we may yet have a chance. Sunspot 720 (as wide as the planet Jupiter) has been a busy lil ol spot, and has shot out another solar flare (this one an X-3!) which has in turn produced another CME that is en route to us.

Look for possible aurora on January 18-19.