The footage, which was being broadcast live by the US space agency, appears to show a blurry object descending towards Earth. Yet, as it looks like it is about to enter our atmosphere the live feed stops, according to footage recorded by alien conspiracy theorists. There have been several similar claims made with videos uploaded to YouTube, but in many cases the alleged UFOs ended up being nothing more than light reflections or lens flares.

NASA The 'UFO' as captured on film before the live stream went down.

This is when light refracts inside the lens and then anomalies are projected onto the video image as if they are objects outside the camera when this is not the case. Despite this and the apparent similarity between the new UFO and earlier lens flare cases, the video filmed on Saturday has sent UFO spotters into another frenzy, amid claims it is proof of alien life and a widespread NASA cover up. But other armchair experts have suggested the object could be a meteor, or even the Chinese space station Tiangong-1. The eight-tonne spacecraft was due to return to ground in a controlled crash – but its operators have lost contact with the unmanned ship and fear it could smash into an inhabited area.

This one pulsates exactly like the other YouTube NASA video, which also cut out, of three similar craft leaving Earth's atmosphere. Jim H on YouTube

Alien hunter Streetcap1, who posted the video online, said: “Remember a UFO is an unidentified object. “This could well be a meteor or the like. “What made it interesting was the camera cut off when the UFO seemed to stop.” Youtube user Jim H said: “This one pulsates exactly like the other YouTube NASA video, which also cut out, of three similar craft leaving Earth's atmosphere. “Coincidence? I think not.”

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