A video proports to show some kind of alien spacecraft.
So assuming this is not simply a fake computer generated video, what might it be?
My first thought was that it might be a kite, however the video seems to show the object moving off into the distance to a degree a tethered kite could not.
My next thought was some kind of custom remote controlled flying wing, possibly with added LED lighting. perhaps something like a Swinglet:
Or an eBee:
The problem with these is they all have a visible propellor. However a bit more research led to the EDF, the Electric Ducted Fan - a type of electric engine that can be mounted either on top of the RC aircraft, or internally in such a way as to be invisible from the ground.
The above two images have been shared on Facebook as evidence that the torching of a police car at the "Million Mask March" demonstration in London was staged by the authorities. But while the car itself was actually set on fire, the image on the left is an entirely unrelated image taken on April 21, 2011 by Josh Reynolds, and posted on his Flickr account:
The meme is shared as a single image (originally one photo above the other, I moved it side by side for this post). This presents some brief obstacles...
Tracking down planes that make particular contrails is something I do quite a bit. So I've made this video showing how I do it, with the hope that it will be useful to other people doing the same thing.
I also discuss in the video why planes sometimes fly in a holding pattern, or make sharp turns, often hundreds of miles from their destination airport. They do this to adjust their arrival time, so they they can fit into their slot in the arrival queue at busy airports.
This video, uploaded June 25th 2015, appears to show two very different colored contrails, one described as "red" (although it's more of an orange pink, like a sunset cloud), and one "blue" (but really more like a normal white contrail).
The planes themselves are barely visible in the video, appearing only when reflections from the sun highlight a spot on the plane. There seems to be quite a long gap between the plane and when the contrail is first visible.
The two planes appear to be flying very similar routes, even appearing to curve in sync at one point (although it's not clear if that's a camera distortion). Regardless, they seem to be flying roughly together.
A popular video claims to show an object in the sky that resembles a "second sun". However analysis of the video proves that what is shown is an offset lens reflection of the Sun itself. There is nothing else in the sky. The effect is also not a sun-dog, an atmospheric reflection, or a mirage. It's just a reflection happening at the camera.
We can see this quite clearly if we stabilize the video so the background is fixed. We can then see the reflection moving with the camera motion. Notice how the small movements of the reflection are in sync with the large movements of the lens flare....
A video is being widely shared on social media (and the "weird news" sections of more traditional media) claiming to show the image of an impossibly large city rising above the fog in the city of Foshan (佛山), Guangdong province, China
Here's a composite image of the Foshan video
Notice the scale of things here, there are what looks like two construction cranes on the "horizon" to the left, and the buildings seem to loom high into the sky above them.
Interesting sunrise contrail, not sunset like most of this type of thing. Less commonly observed, mostly because people are still in bed. Here the contrail develops in sections as it passes through bands of moisture. You can see those bands of moisture reflected somewhat in the bands of cloud (although the clouds are probably not at the exact same altitude).