Mars rover sensors may not be sensitive enough to find signs of life

While testing Mars rover sensors within the Atacama desert, researchers inadvertently discovered a wide range of unclassifiable microorganisms referred to as “the dark biome”

By Leah Crane

The scientific devices we now have despatched to Mars could not be capable to detect indicators of life there. Tests of those devices on samples from the Atacama desert in Chile have proven that they is probably not delicate sufficient to identify organic materials, even when it does exist on Mars.

Armando Azua-Bustos on the Spanish Astrobiology Centre in Madrid and his colleagues took samples in a area of the desert referred to as Red Stone, the place the mud is purple as a result of it is filled with hematite, the identical mineral that offers Mars its rusty color. “This is probably the most Mars-like place on Earth,” says Azua-Bustos. “Being there is almost like being on Mars, except for the colour of the sky.”

When they used state-of-the-art scientific devices – the kind solely obtainable in laboratories on Earth – to analyse the make-up of their samples, they discovered as much as 1 microgram of DNA per gram of soil. This included DNA from 19 species of micro organism and two fungi.

However, practically half of the microbial DNA didn’t match something within the genetic databases we now have, main the researchers to consult with these microbes as “the dark microbiome”. This may imply that they’re organisms that haven’t beforehand been found, or that they’re relics from organisms that lived within the space lots of of tens of millions of years in the past. “We know the microorganisms are there, we have the sequences, but we cannot tell you what they are,” says Azua-Bustos.

When the researchers examined their samples utilizing devices akin to those on present Mars rovers and people deliberate for the close to future, these devices may barely detect any microbial materials, darkish or in any other case. “If you were an alien coming to Earth and you happened to land in the Atacama desert with instruments like the ones we have on Mars, you might say Earth is uninhabited,” says Azua-Bustos. “If those instruments are not able to detect the things that we know are on this site, how are they going to see anything on Mars where we don’t even know what we’re going to find?”

If there was ever life on Mars, which means that our spacecraft most likely wouldn’t be capable to discover convincing proof of it. “We must be cautious about interpreting absence of strong evidence of life as evidence of its absence,” wrote Carol Stoker at NASA Ames Research Center in California in a remark piece accompanying the paper. To make certain about any detection of indicators of life on Mars, we’ll need to deliver samples again to Earth to analyse them – a job which NASA plans to undertake within the late 2020s.

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