A team from Sheffield University collected organisms from high in the stratosphere which, they claim, are too large to have originated on this planet.
Professor Milton Wainwright, who led the project, said the results could be revolutionary, and “completely change our view of biology and evolution”.
Prof Wainwright yesterday told The Scotsman: “These are some very unusual species indeed. We have been carrying out this research for the past 12 years but we haven’t seen anything like this until now.
“Before, we found bacteria which is interesting to us but not to the public at large. So when these first came up on the computer, it was unbelievable. We are talking about complex organisms with, for example, a proboscis, two nostril-like openings, and what is in effect a sphincter.”
He went on: “If life does continue to arrive from space then we have to completely change our view of biology and evolution.
“In the absence of a mechanism by which large particles like these can be transported to the stratosphere, we can only conclude that the biological entities originated from space.
“Our conclusion, then, is that life is continually arriving to Earth from space, life is not restricted to this planet and it almost certainly did not originate here.”
The discovery was made after a research balloon was sent 27 kilometres into the sky before it was burst and parachuted to the ground, carrying samples.
The balloon was launched near Chester and carried microscope “studs” which were only exposed to the atmosphere when it reached heights of between 22km and 27km from Earth.
It later landed safely and intact near Wakefield, West Yorkshire, after which scientists discovered they had captured a fragment of a diatom – a major group of algae – and some biological entities, which were unusual given their size.
After studying them, the team concluded the entities originate from comets – huge balls of ice travelling through space.
The samples were collected during a meteorite shower and the research team now plans to launch another balloon next month in an attempt to secure the same results.
Prof Wainwright, from the university’s department of molecular biology and biotechnology, went on: “Most people will assume that these biological particles must have just drifted up to the stratosphere from Earth, but it is generally accepted that a particle of the size found cannot be lifted from Earth to heights of, for example, 27km. The only known exception is by a violent volcanic eruption, none of which occurred within three years of the sampling trip.”
The findings have been published in the Journal of Cosmology and updated versions will appear in the same journal, a new edition of which will be published in the near future.
Prof Wainwright said that he expected many critics to seize on his findings and attempt to dismiss their conclusions, but said he and his team were determined to collect more samples.
He said balloons can now be launched for little more than £1,500 – far less than the previous balloons sent into the sky – due to new techniques employed by the team’s engineers.
He added: “We are going up again on 20 October, depending on the weather and wind, as there is a meteorite shower from Halley’s Comet, and these particles are thought to be from comets. This time we’ll take a camera.”