The following video is absolutely stunning! It shows a UFO flying at low altitude and supersonic speed above Silicon Valley, California.
The video was recorded by a 4K ultra-HD camera, attached to a DJI Inspire 1 drone.
The experts who analyzed the video estimated that the unidentified flying object was probably metallic in nature – as it reflected sunlight – and it was silently moving at a speed of 1500 – 2000 miles per hour.
One YouTube user estimated the distance traveled as around one mile every one to two seconds.
That would give it a speed of around 2890 km/h (i.e. 1800 miles/hour), roughly 2.4 times the speed of sound.
And here you can watch it in Full HD and x25 slow motion: