Saturn’s moon Enceladus continuously ejects vast quantities of ice particles into space, originating from its subsurface ocean. Researchers of the Planetary Sciences and Remote Sensing Working Group at Freie Universität Berlin and researches at the University of Stuttgart have now chemically analyzed freshly emitted particles originating directly from Enceladus’ subsurface ocean. To do this, they used data from the Cassini space probe. They were able to detect intermediates of potentially biologically relevant organic molecules, which were thus discovered for the first time in ice particles from an ocean outside Earth. The results of the study have been published in the journal Nature Astronomy. 

In 2008, Cassini flew twenty-one kilometers above the moon’s surface to the edge of the “ice and gas plume.” The data collected in this process therefore originates from fresh ice particles that had been in the satellite’s interior just a few minutes earlier. Dr. Nozair Khawaja from the Planetary Sciences and Remote Sensing Working Group, who led the study, has now evaluated these measurements together with doctoral student Thomas R. O’Sullivan, his Stuttgart colleague Professor Ralf Srama from the IRS, and other researchers from the Planetary Sciences and Remote Sensing Working Group led by Professor Frank Postberg at Freie Universität Berlin. Researchers from the USA and Japan also participated in the study.

“Our analysis confirms the results obtained from the analysis of other Cassini data,” says Khawaja. “We can now be fairly certain that both the simple and complex compounds discovered in older ice grains in Saturn’s E ring also originate from the ocean of Enceladus. We suspect that these molecules potentially synthesized at the so-called hydrothermal fields on Enceladus – these are vents at the bottom of the ocean from which hot water rises. In Earth’s oceans, there is evidence of life around similar types of hydrothermal vents.

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Publication:

Khawaja, N., Postberg, F., O’Sullivan, T.R. et al. “Detection of Organic Compounds in Freshly Ejected Ice Grains from Enceladus’s Ocean.” Nature Astronomy (2025). https://doi.org/10.1038/s41550-025-02655-y.

Contact:

Dr. Nozair Khawaja, Planetary Science and Remote Sensing Group, Institute of Geological Sciences, Department of Earth Sciences, Freie Universität Berlin, Email: nozair.khawaja@fu-berlin.de