The Russian press agency ITAR-TASS is reporting something so surprising that I'm having a hard time believing it: Cosmonauts have found microorganisms on the exterior of the International Space Station. Russian scientists are shocked by this discovery and can't really explain how it is possible.
According to the chief of the Russian ISS orbital mission, Vladimir Solovjev, these findings "are absolutely unique."
We have found traces of sea plankton and microscopic particles on the illuminator surface. This should be studied further.
At this point the Russian space agency can't really explain how sea plankton ended on the International Space Station. They have discarded spaceships taking the microorganisms there. Their only explanation is that atmospheric currents may be lifting these particles from the ocean all the way to the station, 205 miles (330 kilometers) up in the sky—which seems absolutely nuts to me:
Plankton in these stages of development could be found on the surface of the oceans. This is not typical for Baikonur. It means that there are some uplifting air currents which reach the station and settle on its surface.
The microorganisms were found on samples collected by the cosmonauts during a space walk. It was a complete surprise when they analyzed them, as they only expected for find the contaminants produced by the engines of the incoming and outgoing spaceship traffic.
It is not clear if the organisms were growing or multiplying but, if confirmed, this discovery may give even more credibility to the theory that organic life may have spread across space traveling on comets and asteroids.
Top image of diatoms by Prof. Gordon T. Taylor, Stony Brook University