An air passenger on a KLM flight believes he may have filmed a UFO through his window as the plane took off from Amsterdam Airport Schipol.
The video was filmed on an iPhone, and the passenger reportedly did not notice the object in the background until the next day.
A blogger on gather.com suggests the evidence supporting the theory it is a UFO includes: "Any usual explanation, such as weather balloon or Chinese lanterns doesn't seem to apply. It's inconceivable airport officials would allow hovering objects free reign over airspace crawling with passenger jets arriving and departing."
So, just as he asks, what do you think it is? Take a look at the video below: