A rain of mysterious strands of wispy, white 'angel hair' fell from the sky in Portugal - leaving locals baffled by the substance, which seems to "come alive" under ultraviolet light.
Some have even questioned whether it was of terrestrial origin - or left drifting in the air by a passing UFO.
One local, who did not want to be named, said, "It fell during the afternoon. I tried to inquire if aeroplanes flew over before, but no straight answer. It happened 2 weekends in a row.
"Me and a couple of friends sent it to be analyzed - and the weirdest things happened. It reacts to UV light. It comes alive." Similar sightings of strands falling from the sky have been reported in countries such as Finland and Canada - but the samples often evaporate before they can be properly analyzed. Conspiracy theorists believe they could be related to UFO propulsion systems - or even to "chemtrails", sinister biological agents supposedly distributed by aircraft around the world.
Nigel Watson, author of the UFO Investigations Manual (Haynes Publishing, 2014), says, "Sightings of UFOs were commonly associated with angel hair up to the 1970s, and in the past it has been seen in association with religious visions in the sky, such as in Fatima, Portugal in 1917."
"These fine fibers falling from the sky were regarded as being the byproduct of UFO propulsion systems, although skeptics tend to explain themas being created by migrating spiders or by dust particles polarized by atmospheric electricity and are a natural phenomenon. It is only in recent years that angel hair sightings have returned again. Samples quickly evaporate making it difficult to analyze their composition and nature."
We are constantly uncovering new species of life on earth. Perhaps something lives in our atmosphere which we cannot see or detect with radar.