SPACE

New research shows that the Martian robots’ sensors may not be sensitive enough to detect life on the red planet. Samples of Martian soil must be brought to Earth, say scientists.

According to a new research study could the instruments aboard the Mars rovers that have been driving around the red planet for years have missed signs of life. The research has been published in Nature Communications and the work was led by Armando Azua-Bustos at the Spanish Center de Astrobiología.

The researchers have tested various sensors in the Chilean Atacama Desert in an area geologically reminiscent of Mars. Compared to more modern technology, both the instruments on board Curiosity and Perseverance have significantly more difficulty detecting microorganisms.

The sensors missed the signs of life

The tests were done at what was once a river delta in the desert. The deposits in the desert were formed about 160 to 100 million years ago under very dry conditions and are reminiscent of Jezero Crater on Mars – where the Perserverance rover is located.

Using modern technology, the researchers managed to see signs, albeit small, of both dead and living microorganisms. Replicas of the sensors on Curiosity and Perserverance performed worse and could barely detect the organic matter.

If there is life on Mars, it is believed to be under similar conditions to where the tests were conducted. The researchers therefore conclude from their results that soil samples need to be brought back to Earth to be able to determine once and for all whether there has ever been life on Mars.

Perseverance in its third year

Curiosity landed on Mars in 2012 and has since explored the area around Gale Crater, collecting rock, soil and air samples. On board are ten instruments, seventeen cameras and various tools for analyzing rock and soil.

Perseverance landed on Mars on February 18, 2021 and has recently entered its third year on the planet. The robot, which has six wheels and is propelled forward by atomic energy, is investigating the geology of Mars with several instruments. Perseverance has collected soil samples and dropped capsules of soil on the ground for possible pickup by future expeditions that can bring the samples to Earth for analysis.

The next big planned rover is called Rosalind Franklin or Exomars and has been developed by Esa. The craft was supposed to be launched in 2022, but after Esa ended its cooperation with Russian Roskosmos, this has been moved forward and may be delayed until as late as 2028. The researchers tested the instruments that will be on Exomars, but even there they had difficulty detecting signs of organic materials.