So perhaps we, the earthlings, are extra-terrestrial too! Particulate matter in our stratosphere proves the existence of extra-terrestrial life, the beginning of our human life too, and even shows that it could have originated from space, say experts from the University of Sheffield and the University of Buckingham Centre for Astrobiology, according to The Independent.

Professor Milton Wainwright and his team hit upon the theory after they sent a balloon into the stratosphere 27 kms into the atmosphere above Sheffield during the Perseid meteor shower last year. The balloon contained sterile slides which could document tiny biological organisms.

One of the slides shot a particle sized at about 10 microns, which Wainwright said was titled "the dragon particle" made of carbon and oxygen and was therefore not part of cosmic or volcanic dust. However, Prof Wainwright added that it was not clear whether it was single or composed of much smaller microbes. He was also firm in his statement that though the entity was biological, it was like nothing found on earth. "What is amazing is that these organisms appear on the sampling stubs in an absolutely pristine condition," he told The Independent. He emphasized the lack of "pollen, grass or pollution particles" on them, or even soil or volcanic dust. Unless by some methods they are lifted from Earth and "sieved" out from other particles, they seem to be coming from outer space.

Moreover, some of these samples produced "impact craters" when they hit the sampler. Indeed, that makes it clear that they have come from space. If proven, then our findings of life as well as evolution would be challenged. Our very text-books would have to be challenged, he said to Express.co. He pointed out that diatoms are "raining down on Earth," and will change all our theories about biology and evolution. Professor Chandra Wickramasinghe told Express that "algae-like organisms" have also been discovered on the meteorite that has fallen on earth.

Refuting these claims, an astrobiologist told Space.com that the findings cannot be attributed to alien life, which would require "extraordinary proof." Moreover, can the experts prove that it was made up of D amino acids instead of L amino acids? It needs to made of biochemistry that is different from other organisms.The Journal of Cosmology itself has been doubted by many scientists.

However, Professor Wainwright's claims come just weeks after Russian scientists say they have found traces of marine life on the exterior of the International Space Station (ISS). Vladimir Solovyev, an official in charge of ISS, told the news agency Itar-Tass that tiny plankton and microscopic organisms had been found on the spacecraft's exterior, and said it was an "absolutely unique" finding.

A year ago, Prof Wainwright had confirmed that he was "95 percent convinced" that the organisms captured on the slides were not from the earth, but from space. Pointing out that there is no known method by which we can prove that these forms can go to that height from earth, people still mistakenly believe that they must have originated in the earth. But some samples had cosmic dust on them, which showed that they came from space. Otherwise, had they originated from the earth, they would have pollen on them.

Being biological entities from space, even though they cannot be completely certain about it, it is clear that they are originating from comets. Some particles are clean, without dust, which also proves that they have not come in contact with earth. As cosmic dust is also not on them, it looks as if they come from an "aquatic environment,", the most visible part of which is a comet in space.