Cosmonauts have apparently discovered plankton and other microorganisms on the outside of the International Space Station's windows, according to an announcement from a Russian official. NASA has not yet confirmed or denied the findings.
"As far as we're concerned, we haven't heard any official reports from our Roscosmos colleagues that they've found sea plankton," NASA spokesman Dan Huot told Space.com. Roscosmos is Russia's Federal Space Agency.
The Russian cosmonauts allegedly found the plankton during a routine window cleaning. The plankton were not visible to the naked eye??a machine detected the particles when it analyzed the contents of the window wipes.
It's not clear whether the plankton were living or dead, but there is evidence that microorganisms can survive the freezing conditions and harsh radiation of space.