The sun reflects off the water in this picture taken by German astronaut Alexander Gerst from the International Space Station and sent on his Twitter feed July 17, 2014.
The sun reflects off the water in this picture taken by German astronaut Alexander Gerst from the International Space Station and sent on his Twitter feed July 17, 2014. Reuters

Residents in Portugal spotted mysterious strands of "angel hair" falling down from the sky. The incident has been caught on camera as many wondered if the strands came from a passing UFO. Locals who witnessed the rain of angel hair thought the strands appear to be "alive" when exposed to ultraviolet light.

One resident, who asked not be named, told Metro that the wisps of hair fell in the afternoon. He had tried to ask if an aircraft had passed by before but he found no answer. The rain of hair has happened for 2 weekends in a row, he said.

The local said that he and his friends had the angel hair analysed. They found it weird that it would react to UV light and "come alive." According to reports, similar sightings of strands falling from the sky were also reported in Canada and Finland. Before someone could properly study the strands, the samples usually evaporate.

Conspiracy theorists who have heard or seen such strands believe they are associated with the propulsions systems of alien spacecraft. Some also said the strands are "chemtrails" or dangerous biological agents which can be disseminated by some type of aircraft across the world.

Nigel Watson, author of the Haynes Manual for UFO Investigators, the sightings of UFOs related to angel hair were reported up to the 1970s but they were previously linked to "religious visions" in the sky like a previous incident in 1917 in Portugal. Past reports of angel hair were associated with manifestations of the Virgin Mary, according to AOL.

The angel hair was named from fine hair or spider webs. Scientific explanations of angel hair falling from the sky suggest the source as an atmospheric natural phenomenon caused by spiders. The report said that some types of spiders can move from one place to another through air and sometimes on cobweb gliders when migrating in large numbers.

Sightings of hair or gossamer threads of Linyphiidae spiders have been reported in Australia, Britain and New Zealand. Aside from spiders, another scientific explanation for the alleged UFO angel hair may be blamed on atmospheric electricity causing polarised dust particles to float and combine to form long hair-like filaments.

(Source: YouTube/NunoReis)