NASA's Curiosity Rover has tested a new technique to search for molecules that could reveal the signs of alien life on Mars.
While the experiment conducted with the Sample Analysis at Mars (SAM) instrument has so far failed to deliver any signs of life on the Red Planet, it proves the technique's viability for future missions, possibly on worlds more distant than Mars, such as Saturn's moon Titan.
The results from the first SAM tests are detailed in a paper published in the journal Nature Astronomy.
Since its arrival on Mars in 2012, the SUV-sized Curiosity Rover has been exploring the nature and extent of ancient habitable environments in Gale Crater. This has included the search for organic compounds made up of elements like carbon, nitrogen and oxygen.
From there, SAM is used to investigate the origins of these organic molecules to see if they are abiotic—not derived from living organisms—or if they could be biotic in origin, produced by the processes that sustain life.
Another possible origin for organic molecules would be prebiotic, these being the kind of molecules that we believe could have led to the development of life on Earth.
To conduct this experiment, in March 2017 the Curiosity Rover scooped up material from an area of Mars known as the Bagnold Dunes, a 22-mile long group of dark grey dunes in the Gale Crater, the first dune system on another planet ever explored by humanity.
These samples were transferred to SAM, which is made up of three different instruments. Among these is a mass spectrometer that is designed to isolate and identify the key elements necessary for life.
Additionally, SAM has a wheel of 74 storage holders, some of which contain chemical solvents that allow the rover to conduct so-called "wet chemistry," and others that are made of quartz, allowing Curiosity to bake samples.
The new results related to a test in December 2017, which used these solvents to dissolve substances to search for organic molecules.
The researchers involved in the study spent several years analyzing the results of this wet chemistry experiment conducted by SAM. They found organic molecules that would have been missed in the rover's normal sample analysis.
This helps verify that such experimentation could be a valuable tool in the search for life on the surface of alien worlds. Unfortunately, what the team didn't find was any evidence of life, such as amino acids or other complex organic molecules.
Georgetown University researcher Maëva Millan is the lead author of the study describing the SAM results. She told the New Scientist: "We have proved that this experiment can work. That means we can do this same experiment again on different minerals like clay and sulfates that can better preserve organic molecules."
The wet chemistry technique used by SAM will continue to be used by Curiosity during its ongoing mission of exploring the Gale Crater, but it will also be used by an upcoming rover to examine other areas of Mars.
The European Space Agency will send the Rosalind Franklin Rover to Mars in 2022 as part of its ExoMars program. The rover, named after pioneering chemist Rosalind Elsie Franklin whose work helped understand the structure of DNA, will land in the Oxia Planum area of Mars.
The new rover will search this region, which researchers believe is an ancient lake, for signs of life either in the past or currently. And its Mars Organic Molecule Analyzer (MOMA) will use a technique similar to the now verified wet chemistry method to do this.
The method will also be used beyond Mars when NASA's Dragonfly mission visits Saturn's moon Titan. The rotor-operated space-drone will search for the building blocks of life around Saturn's icy moon upon its planned arrival in 2034.
Uncommon Knowledge
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Newsweek is committed to challenging conventional wisdom and finding connections in the search for common ground.
