There is unexpected life in this piece of asteroid

An alien sample harbors life, but not the kind you think. While the Japanese space agency, Jaxa, had taken care to bring back pieces of asteroid from space by sealing them in a container, their analysis surprised scientists. They discovered that one of the samples was already covered in… terrestrial life.

This discovery was detailed on November 13, 2024 in the journal Meteoritics & Planetary Scienceand spotted by the media Space on November 27. The samples studied by scientists are those from the Hayabusa 2 mission, which returned to Earth with samples from the asteroid Ryugu in 2020. For the second time in the history of humanity, pieces of an asteroid were brought back to our planet.

Pieces of asteroid colonized by terrestrial life

These samples are therefore rare and all precautions have been taken to keep them intact. However, the new study reveals that a valuable sample from Ryugu was quickly overrun by terrestrial life.

« We report the discovery of stem and filaments of organic matter, interpreted as filamentous microorganisms, on a sample of (162173) Ryugu recovered by the Hayabusa 2 mission », Write the researchers in their study. By analyzing one of Ryugu’s fragments, scientists discovered the microorganisms and observed their behavior. “ They appeared on the rock and spread before dying », Describes planetologist Matthew Genge of Imperial College London, who carried out the study, to the media Space.

The evolution of the number of microorganisms confirmed to scientists that they were alive. Furthermore, they demonstrated that the colonization of the sample by this form of terrestrial life was very recent. Researchers aren’t sure, but the microorganisms could be bacteria of the genus Bacillus, which are often found in soil and rocks — but their DNA would need to be studied to verify this.

Could scientists be wrong?

However, could it be that scientists were wrong, and that this life is in fact of extraterrestrial origin? This is highly unlikely, since the researchers began by performing tomography on the sample (an x-ray method that allows information about the sample to be obtained). However, at this stage, no microorganisms were spotted on the sample. Life appeared later, once the rock was exposed to the Earth’s atmosphere.

Even if this study does not tell us anything about extraterrestrial life, it is useful for better understanding the problem of terrestrial contamination. Over the next few years, humanity plans to bring Martian samples back to Earth. We already know that it will certainly be very complex to detect extraterrestrial life there, assuming it is present there. And above all, it will be necessary to be able to ensure that this is not the result of terrestrial contamination when handling the sample.