Biomarkers on the Icy Jovian Moons: Can Europa Also Provide Insights into Life’s Origin?

Within the payloads of JUICE and Europa Clipper, there are instruments suitable for the search of specific biosignatures that can diagnose life tracks in two ways.

The payloads include mass spectrometers capable of measuring isotopic abundances for identifying life, and chromatography instruments testing whether ocean worlds harbor amphiphile mixtures, which would lead to a lipid-first origin of life.

In this paper we describe how the two missions may begin to test whether there may be large detectable excursions of stable isotopes of chemical elements on the icy surfaces of the Jovian icy moons that are substantially shifted from their expected isotopic distributions.

IMAGE

This instrumentation is carried on the Europa Clipper mission. (a) MASPEX (Mass Spectrometer for Planetary EXploration) measures volatile and organic molecules, including amphiphilic lipids in Europa’s sputtered exosphere as well as ocean plumes. (b) SUDA (SUrface Dust Analyzer) is a dust/ice mass spectrometer, analyzing salts and organics in grains. The results would possibly support the lipid world origin — Life

The detection of an unambiguous signal would suggest a biogenic origin, provided care is taken to exclude abiotic thermal isotopic fractionation. Our suggested tests should be confirmed independently with other techniques. Stable isotope geochemistry on the icy Jovian moons has not yet been thoroughly discussed in the literature.

In addition, we enquire whether insights into life’s origin could be retrieved from Europa’s ocean and surface, including the question of the first steps in the evolution of life. Special emphasis has been put on an approach to seek on the surface of ocean worlds chemical phenomena that are rather primitive, such as reproducing lipid micelles as roots of protocells, but nevertheless can predict a path towards life with published models.

(a) A portable instrument using Capillary Electrophoresis Laser-Induced Fluorescence (CE-LIF) technology is being developed and tested by NASA’s Jet Propulsion Laboratory (JPL) (Pasadena, CA, USA) for future missions to search for evidence of extraterrestrial life. (b) CytoFLEX is a nano-type flow cytometer that would analyze potential living cells and also nanoscopic reproducing micellar protocells — Life

Biomarkers on the Icy Jovian Moons: Can Europa Also Provide Insights into Life’s Origin?, Life (open access)

Astrobiology,