Unusual footage from China. There was a mysterious object in the sky. Observers decided that it was ... UFOs. Others think it's a strange cloud. Then everything went away, and explanations were absent

http://www.latest-ufo-sightings.net/2017/09/black-ring-caught-tape-jefferson-city-missouri-17-sep-2017.html

Witness report: Black ring hovering and sky. At first it looked like smoke. As we approached it looked more solid
My wife and I were driving north on Highway 54. Approximately 10 miles S. of Jefferson City. She brought to my attention this black ring in the sky in front of us. I was driving so she grabbed her phone to take a photo. After the snapshot, she took it upon herself to start recording video. Good move. After discussing it and trying to understand what we just saw, I wish we would’ve stopped to study it closer.
We did check the review mirrors as we drove out of sight. The object was still there as we drove away.
At first we thought it was a smoke ring. But as we approached it, the black ring looked dense. It definitely was not smoke.
If I had to guess it was approximately 500 feet high. And 30 to 50 feet in diameter. The object was stationary as we passed by.

"Stunned eyewitnesses filmed the phenomenon with their smartphones in the small town of Progreso de Madero in the Quecholac municipality of central Mexico's Puebla state.

The footage, which shows a huge black ring hovering in the sky, left local residents baffled.

Some were convinced that it was a flying saucer while others, pointing out that it was partially enveloped in cloud, thought it was a weather-related phenomenon.
Eyewitnesses can be heard in the background of the video trying to explain the apparition.

One woman asks: "What is that?", and a man replies: "A flying saucer?"

Another woman speculates: "It's a rain formation", but the man counters: "No, it's not, it's a black wheel", and the woman notes: "It's going up."

The black ring quickly disappeared from view and there is still no official explanation for it.

Netizen 'Alejandro Lopez Robles' was convinced he had seen something otherworldly, commenting: "It's a flying saucer."

Bloomington, MN April 2017 https://www.mufoncms.com/files_jeud8334j/83477_submitter_file1__IMG4994.JPG

I saw this ring of lights last sat night, April 29, 2017. The lights were in the western sky, and it was an overcast night. The ring of lights were stationary and did not move at all for many hours. The lights were coming from behind the clouds.

November 2014 flying saucer wave in Houston

February 2017 in New York http://www.texasufosightings.com/buzz/strange-smoke-ring-over-new-york-see-photo