A downward lightning negative ground flash captured at 7,207 images per second. A negative stepped leader emerges from the cloud and connects with the ground forming a return stroke.

From ZT Research, who is “trying to figure out how lightning works.”

via Stellar.

How does lightning form? Evidently we’re still trying to figure it out! It all starts in the clouds where both ice crystals and hail stones form: 

Scientists believe that as these hail stones fall back through the rising ice crystals, millions of tiny collisions occur. These collisions build up an electric charge which is stored in the cloud like a battery. ”A cloud is very much like a battery, but a battery with a much higher voltage than your typical flashlight battery… not 1.5 volts but 100 million volts.”

But what scientists don’t know is exactly how this electric charge generates lightning. “What remains a major meteorological mystery is how it is that ice particle collisions result in the generation of lightning. We’re very much in the middle ages on that problem.”

From the Discovery Channel’s “Raging Planet” series.

Night Time Lapse of Comet Lovejoy (C/2011 W3) rising above the Andes near Santiago de Chile, 23rd December 2011, just before sunrise. Set of 4 sequences taken with different lenses “zooming in” the scene.

Comet Lovejoy was just discovered in late November 2011 by amateur astronomer Terry Lovejoy “using a camera on his wide-field 8-inch Schmidt-Cassegrain telescope from his home in Brisbane, Australia.” There’s really great additional background about both Lovejoys (the rare comet and the man — who had discovered two other comets before this one) at Astro Bob.

via Kottke.

We’ve been looking for a good murmuration of starlings video for a month or two, but had never quite connected with the ones we’d found. And then we saw this one!

Two more informative links about the reasons and physics behind them, one with video.

Thanks, @hilahil.