IS IT a bird, is it a plane, is it ... a piece of paper?

As of Thursday, people from as far away as Berlin in Germany and Winnipeg in Canada were reporting spotting paper planes that were recently released from the upper atmosphere by an ambitious team of amateur scientists.

Watch the video of the launch below

The Project Space Planes team - fronted by Joel Veitch, a British web animator - is attempting to snatch the world record for the longest flight by a paper plane.

It launched a weather balloon carrying 200 of the planes on Tuesday from a site near Wolfsburg, Germany.

The planes were released once the balloon reached an altitude of about 36,500m and a video camera captured the projectiles gliding toward the Earth's cloud cover below. The balloon then burst at about 37,339m and arrived back on the ground within 40 minutes, over 300km from the launch site.

Samsung latched onto the project, providing SD cards to be attached to each plane as an apparent publicity stunt to "prove how tough their memory cards are," the project's website said.

"People from all over the world have been uploading messages onto our website," Veitch explained in a YouTube video.

"We put those messages onto these memory cards … people find the memory cards, put them into their computer … they will get the messages from people all over the world and we will get to find out how far these planes have gone."

The project has received unconfirmed reports of paper plane sightings in the German cities of Minden, Bremen and Berlin, according to its website.

There were also reports that the planes landed as far away as the city of Turlock in Northern California and Winnipeg, Canada, while others may have landed in South Africa and The Netherlands.