It seems increasingly feasible to detect life on frozen moons on Mars and the outer solar system. According to a new paper published in the journal Biology, Alberto Farran of the Center for Astrobiology in Madrid, Spain, and his colleagues have developed a new tool to detect life on other planets.
Gravel or microbes? In fact, it is a cluster of E. coli. But sometimes it’s hard to tell, so we need new recognition tools.
This tool is called “CMOLD” – a complex molecular detector. With this tool, they solved one of the main scientific challenges in the field of interstellar exploration: how to detect life on other planets using only robotic landers.
Previous life detection instruments used gas chromatography-mass spectrometers (GC-MS) to look for volatile organic compounds. These devices were used by the Pirate lander in the 1970s, the curiosity Mars rover and the upcoming European ExoMars Mars Exploration Program. These devices heat the sample, isolate the component elements in the sample, and then identify the elements by spectral signals.
But CMOLD works a little differently. It extracts organic molecules from suspended liquids and then applies three powerful analytical techniques: (1) microscopes – looking for microscopic visual evidence of life; (2) Raman spectrometers – detecting atomic composition and organic molecules; and (3) biomarker detectors, which contain antibodies and short DNA and RNA molecules that bind to life-related compounds.
The emergence of this new technology is very timely. It makes robotic missions to space for life more competitive than sample-taking projects. NASA, for example, has just launched the Perseverance rover to Mars to launch a sample recall project. Some parts of CMOLD have been extensively tested and are scheduled to fly into space on future missions. For example, the European Space Agency’s Roslind Franklin probe, which is scheduled to launch in 2022, has a Raman spectrometer on its scientific payload. NASA’s proposed mission to Mars a few years ago, the Icebreaker, also includes a biomarker probe. Given these past experiences and the many tests that have been completed, Farran and his colleagues believe that the three-part CMOLD could be put into use in the near future.
The authors say their new instrument is suitable for detecting life we don’t yet know about. Of course, it also depends on how bizarre the so-called “unknown life” is. While it is worth exploring whether biomarkers can give positive signals about biochemistry different from Earth’s, Raman spectrometers do detect complex organic biometric features, even if they do not correspond to known life molecules. Finally, high-resolution optical microscopes are also an important tool for close-up observation of samples.
As a result, CMOLD represents a very promising way to detect life on Mars and frozen moons such as Europe and Enceladus. On Mars and the frozen moons of the outer solar system, if life exists, they should at least have some similarities to the creatures on Earth (with the exception of Titan, the type of biochemistry on Titan may be completely different from that on Earth). However, as we continue to launch more interstellar exploration missions, it is obviously a good thing that CMOLD devices are readily available.