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New publications on the detection of organic material in the salty ice of ocean worlds

News from Sep 06, 2023

Europa and Enceladus, two icy moons of Jupiter and Saturn respectively, have water oceans below their icy surface. These oceans are rich in salts, formed by interactions between oceanic water and rocks at the seafloor.  Enceladus was explored by the Cassini mission, and one of its instruments, the Cosmic Dust Analyzer (CDA), allowed the detection of these salts on the ice grains from a plume which eject water from the ocean to high altitudes. It also detected organic material in these ice grains, including some complex large molecules, but the resolution of the CDA instrument was too low to determine if this organic material originates from lifeforms thriving in the ocean (perhaps at hydrothermal vents similar to those on Earth).

The Europa Clipper mission from NASA will be launched next year and reach the moon Europa near Jupiter in 2030. The successor instrument of the Cosmic Dust Analyzer will be onboard and is called the SUrface Dust Analyzer (SUDA). SUDA has a much better resolution, and the capacity to detect and characterize organic material and salts on ice grains ejected from Europa's surface, indirectly derived from the ocean. Both SUDA and CDA are mass spectrometers which analyze ice grains and provide identification of molecules therein.

In the lab of the Planetary Science research group at FUB, an analogue experiment called LILBID (Laser Induced Liquid Beam Ion Desorption) is used to calibrate both the CDA and SUDA instruments, and reproduce their data in known conditions so as to better interpret the results from space missions. Recently, we performed analogue experiments using LILBID to simulate the data that SUDA would observe when analyzing ice grains from Europa, in the case of ice grains rich in both organics and salts. We show that SUDA has the capacity to detect organics despite the salts (which complicates the mass spectra and can strongly decrease the signal from the organics). The mass spectra recorded with LILBID are gathered in a database that will be used to look for organics in the ice grains of Europa, and may help to find molecular traces of life from the ocean. 

» View Publication "Mass Spectrometric Fingerprints of Organic Compounds in NaClRich Ice Grains from Europa and Enceladus" (a)

» View Publication "Mass Spectrometric Fingerprints of Organic Compounds in SulfateRich Ice Grains: Implications for Europa Clipper" (b)

» Download Publication (a)

» Download Publication (b)

» Habitat-OASIS Website

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