"Bubble cloud" seen near Beijing

YouTube link. 

As reported by ITN (Via Nothing To Do With Arbroath) :

One observer at the Beijing Planetarium described what he saw: "At first, it's relatively small and bright, the upper part is something like a semi-circle, a spherical ring of light, it's obviously becoming bigger and bigger then." The object, which appeared in the sky for fifteen minutes, gradually became bigger and thinner.

This looked very familiar to me, so I searched this morning, and finally found links to reports of a similar phenomenon observed in Hawaii earlier this summer.  Here's how it was reported by Discover Magazine:

The footage is from a webcam mounted outside the CFHT astronomical observatory in Hawaii... You see some stars and the horizon, then suddenly an ethereal pale arc pops into view. It rapidly expands into a thin circular shell, then fades away as it fills the view. The whole thing takes a few minutes to expand; you can see the stars moving during the event...

I blurred the image just a bit to reduce some of the noisy background, and what leaps out is that the expanding halo is limb-brightened, like a soap bubble, and fades with time. That strongly points toward something like a sudden impulse of energy and rapid expansion of material, like an explosion of some kind. Note that the ring itself appears to be moving, as if whatever caused it was moving rapidly as well. It took me a minute after watching the video to remember the bizarre Norway spiral from a couple of years ago, a phenomenal light show caused by an out-of-control rocket booster jetting out fuel in space...

Asterisk board member calvin 737 was the first to suggest it might be related to a Minuteman III missile launch around that time. As more people on the forum dug into it, the timing was found to be right. The missile launched from Vandenberg Air Force Base (in California) at 03:35 Hawaii time, just minutes before the halo was seen...

...the missile is above most of the Earth’s atmosphere, essentially in space. So when that gas is suddenly released from the stage expands, it blows away from the missile in a sphere. Not only that, the release is so rapid it would expand like a spherical shell — which would look like a ring from the ground (the same way a soap bubble looks like a ring). And not only that, but the expanding gas would be moving very rapidly relative to the ground since the missile would’ve been moving rapidly at this point in the flight. 

More at the link, including video of the Hawaiian event.  As a side note, I wonder how much missile fuel is ejected above our planet each year, and what cumulative effect is has on the atmosphere (and on us)...  [Addendum:  see David's info in the Comments].