Advancing the search for extra-terrestrial genomes

Widespread synthesis of complex organics, including nucleobases and ribose precursors, occurred early in the history of the solar system in the solar nebula. These organics, delivered to multiple potentially habitable zones, may have biased the evolution of life towards utilization of similar informational polymers. Meteoritic exchange might also have produced shared ancestry, most plausible for Earth and Mars. To test this hypothesis, we are developing the Search for Extra-Terrestrial Genomes (SETG), a life detection instrument for in-situ isolation and sequencing of nucleic acids. Our mission focus area is astrobiology and the search for life beyond Earth. Our science goal for Mars is to search for related or unrelated nucleic acid-based life, particularly life that has the potential to interact with life on Earth; this may also inform sample selection for Mars Sample Return (MSR) and reduce the risks of false positives through the first in-situ measurement of forward contamination. Our science goal for Enceladus is to search for a second genesis based on nucleic acids in the plumes emanating from the South Polar Region. Life detection may also be possible in Europa orbit but the availability of a suitable plume is tenuous and it is a challenge for biological reagents to survive intense radiation there. Here we describe advancements in SETG geared towards in-situ sequencing during a future Mars mission, including extraction of nucleic acids coupled with proof of principle for in-situ single-molecule nanopore-based sequencing. We briefly describe plans to advance SETG from Technology Readiness Level 3 to 6 in preparation for future flight definition and show that under realistic assumptions, a sensitivity of parts per billion or better is feasible.