Okay, so let's start with the facts: On Dec. 28, the sun spit out a big burst of gas and magnetic field (called a coronal mass ejection), and this stellar burp started hurtling toward Earth. When coronal mass ejections hit Earth's magnetic field at high speeds, the result is a stunning cosmic light show — an aurora.
But you may have read that this recent CME is going to allow you to see the aurora borealis (a.k.a. the northern lights) on New Year's Eve:
I hate to be a party pooper (haha, just kidding, I love being a party pooper) but I also don't want y'all to be disappointed. So let's get a few things straight:
1. While this CME is strong enough to make the aurora borealis more widely visible than usual, we're talking about increased visibility around Oregon and thereabouts. The California Bay Area might just squeak by. This won't be a nationwide viewing opportunity.
2. Yes, this CME is sort-of New-Year's-Eve-adjacent: The peak activity will be visible on Dec. 30, and it could potentially last into New Year's Eve. But as of Wednesday, the Space Weather Prediction Center only predicted minor geomagnetic storms on Dec. 31. The potential for the aurora borealis to show up in Californian skies is based on the "strong" storm predictions for Dec. 30, and it's possible that the strongest activity will be over by the time it gets dark even on Dec. 30.
3. Even if the storms on Dec. 31 really go nuts, that doesn't mean you'll get a dazzling light show in the sky on New Year's Eve. Seeing the aurora borealis is hard. Take it from me: I recently went to Reykjavik, Iceland, which is considered a pretty great place to catch the northern lights, and I was out looking for them on nights with decently high geomagnetic activity. But even the slightest haze in the sky can ruin your aurora viewing plans, and even when we finally got a clear night (and took a boat out into the middle of nowhere to cut down on light pollution), the lights were just the faintest green streak. If you're in San Francisco, you'll have to escape the city lights if you even want a shot.
This isn't to say that you shouldn't be excited about looking for the lights on Wednesday night, especially if you live at a geomagnetic latitude of around 50 degrees or higher. Keep an eye on the Aurora_Alerts Twitter account for updates on the strength of the activity. If you suspect you might be far north enough to see something, find a dark spot and be patient — if the aurora is weak, your eyes could need a lot of time to adjust.