The human crew aboard the International Space Station may not be the only group of living creatures hurtling through space: microscopic sea plankton could also be hitching a ride. Vladimir Solovyev, the official overseeing Russia’s ISS segment, reported on Tuesday that traces of terrestrial sea plankton were on the spacecraft’s exterior, according to the ITAR-TASS
news agency. “Results of the experiment are absolutely unique. We have found traces of sea plankton and microscopic particles on the illuminator surface. This should be studied further,” Solovyev told ITAR-TASS.
The plankton were reportedly discovered while cosmonauts were conducting a study designed to identify residues that could accumulate on the ISS as it travels through space. However, NASA officials aren’t confirming the Russian plankton claim. “I’m not sure where all the sea-plankton talk is coming from,” NASA spokesman Dan Huot told Space.com
Although the reports of plankton haven’t been confirmed, past incidents have shown that microscopic organisms can indeed survive being rocketed into space. Several years ago, scientists launched a group of tardigrades
— the planet’s scrappiest animals — into space. They survived cosmic radiation, freezing temperatures, dehydration and the vacuum of space. In May NASA scientists also reported that the Curiosity rover likely carried dozens of species of bacteria that could have survived a trip to Mars, possibly contaminating the planet.
The source of those critters was straightfoward: Bacteria live nearly everywhere on Earth. But as for plankton, that's less clear. Even Solovyev said he couldn’t explain how the organisms got into space.