Rare sight from space station sparks scramble for answers
An incredible cloud phenomenon appearing to stretch thousands of miles across the Earth has sent conspiracy theorists into a frenzy.
The ominous shape resembles a contrail emitted by an aeroplane but is much longer, seemingly reaching from pole to pole.
Online commenters have pitched a host of fanciful ideas as to what may have caused the formation, but experts say it's simply a rare type of cloud.
It was spotted this week by an eagle-eyed space fan watching a public live feed from the International Space Station.
The mysterious clip was later uploaded to YouTube, baffling conspiracy nuts.
One commenter wrote: "It is a portal for things to travel through unseen/stealth."
Another quipped: "Looks MAN MADE . . . don't you think we should have answers for this???????"
But it turns out the strange line has a far simpler explanation.
One weather expert told The Sun the formation was a rare type of cloud.
David Schultz, a professor of synoptic meteorology at the University of Manchester, reckons a low pressure storm is responsible.
"It looks like the back edge of a cloud associated with an extratropical cyclone - i.e. a low-pressure system. It's unusual, but it is real," he said.
Satellite images showed a chunk of cloud appeared in the vicinity of the line on March 4, experts at the Met Office explained.
It appears to stretch across a massive portion of the Earth because of a trick of the light.
"Combined with the camera's perspective, this is making you think there is a very large shadow covering a big chunk of the earth," a spokesman said.
The perspective trick made the cloud appear "farther and straighter" than the image would have you believe, he added.
Looks like it's tough luck for conspiracy fans - though perhaps it's comforting to know a UFO wasn't blitzing across our skies.
This article originally appeared on The Sun and was reproduced with permission