Scientists examining a rock sample from outer space thought they’d hit the jackpot recently when they discovered that it was teeming with life. But they soon learned that the microbes actually originated on Earth.
Getting the chance to examine extraterrestrial material has to be on the bucket list of every scientist working in the field, but as the team at Imperial College London learned, the activity is fraught with challenges.
They were researching a sample of material from the distant Ryugu asteroid gathered during Japan’s Hayabusa2 mission in 2019 before being brought to Earth in 2020.
The asteroid sample was then divided up among various groups of scientists around the world, paving the way for an array of tests that might uncover evidence of microbial life on the material. Such an exciting discovery could imply that life on Earth might have originated from extraterrestrial sources, or that life can survive and spread across the solar system.
The Ryugu samples were of course treated with great care, with scientists deploying strict contamination controls such as hermetically-sealed transportation and nitrogen-purged clean rooms to limit the chance of contamination.
But despite the special measures, the researchers at Imperial College London ended up finding signs not of alien life, but instead of terrestrial life.
In a recent study titled Rapid colonization of a space-returned Ryugu sample by terrestrial microorganisms, the researchers noted that while initial analysis of the material showed no sign of contamination, rods and filaments of organic matter resembling known terrestrial microbes were found on the sample’s surface within a week of exposure to Earth’s atmosphere.
While the discovery won’t have provided the thrill that the researchers must have been hoping for, it’s still a vitally important one as it shows that even with careful handling, contamination of such highly prized material can still occur, indicating that even more robust safeguards need to be put in place for research work of this nature.
The team’s discovery doesn’t necessarily mean that all of the Ryugu samples in various labs around the world are also contaminated, but it does mean that any claims about the discovery of extraterrestrial life on the material will come under even greater scrutiny than might otherwise have occurred.