While testing the Mars rover’s sensors in the Atacama Desert, researchers inadvertently discovered a variety of unclassifiable microbes called the “dark biome.”
Sky
February 21, 2023
A region of the Atacama Desert called Redstone Armando Azua Bustos
The scientific instruments we sent to Mars may not be able to detect signs of life there.Testing of these instruments on samples from atacama desert Chile shows that it may not be sensitive enough to find biological material, even if it exists on Mars.
Armando Azur Bustos of the Spanish Center for Astrobiology in Madrid and his colleagues collected samples in a desert region called Redstone. The dust is red in this region because it contains a lot of hematite, the same mineral that gives Mars its rusty color. “This is probably the most Mars-like place on Earth,” he says. “Being there is like being on Mars, except for the color of the sky.”
When they used the most advanced scientific instruments – the kind only available in laboratories on Earth – To analyze the composition of the samples, they found up to 1 microgram of DNA per gram of soil. It contained DNA from 19 species of bacteria and 2 fungi.
But almost half of the microbial DNA didn’t match anywhere in our genetic database, leading researchers to refer to them as the “dark microbiome.” This could mean that they are organisms that have never been discovered before, or are the remains of organisms that lived in the area hundreds of millions of years ago. I know, I know the array, but I don’t know what it is,” Azua-Bustos said.
When the researchers tested the samples using instruments similar to those on board current Mars rovers and those planned for the near future, they found that the instruments, dark or otherwise, were microbial. I could barely detect any substance. “If you were an alien coming to Earth, and you happened to land in the Atacama Desert with equipment like you have on Mars, you might say that Earth is uninhabited,” says Azuabustos. “If these instruments can’t detect what we know to be at this site, how can we see anything on Mars that we don’t even know what we’ll find?”
If there is life on Mars, this probably means that the probe will not find convincing evidence of life. In a comment accompanying the paper, Carol Stoker of the NASA Ames Research Center in California said, “We should be cautious about interpreting the lack of strong evidence for life as evidence for the absence of life. To reliably detect signs of life on Mars, samples must be brought back to Earth and analyzed, a task NASA plans to undertake in the late 2020s.
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