Fabian Klenner

University of Washington | UW · Department of Earth and Space Sciences

Icy bodies with subsurface oceans are a prime target for astrobiology investigations, with an increasing number of scientists participating in the planning, development, and realization of space missions to these worlds. Within Germany, the Ocean Worlds and Icy Moons working group of the German Astrobiology Society provides an invaluable platform f...

The Cassini mission provided evidence for a global subsurface ocean and ongoing hydrothermal activity on Enceladus, based on results from Cassini’s mass spectrometers. Laboratory simulations of hydrothermal conditions on icy moons are needed to further constrain the composition of ejected ice grains containing hydrothermally altered organic materia...

Icy moons like Enceladus, and perhaps Europa, emit material sourced from their subsurface oceans into space via plumes of ice grains and gas. Both moons are prime targets for astrobiology investigations. Cassini measurements revealed a large compositional diversity of emitted ice grains with only 1 to 4% of Enceladus’s plume ice grains containing o...

Saturn's large and diffuse E ring is populated by microscopic water ice dust particles, which originate from the Enceladus plume. Cassini’s Cosmic Dust Analyser (CDA) sampled these ice grains, revealing three compositional particle types with different concentrations of salts and organics. Here we present the analysis of CDA mass spectra from sever...

The concept of a biosignature is widely used in astrobiology to suggest a link between some observation and a biological cause, given some context. The term itself has been defined and used in several ways in different parts of the scientific community involved in the search for past or present life on Earth and beyond. With the ongoing acceleratio...

The surface ice of Europa is known to contain high proportions of inorganic material that could heavily influence the compositional analysis of organic compounds in ejecta ice grains by the SUrface Dust Analyzer (SUDA) impact ionization mass spectrometer onboard NASA’s Europa Clipper mission. We previously have analyzed the effects of NaCl on the m...

Saturn’s moon Enceladus harbours a global ¹ ice-covered water ocean 2,3 . The Cassini spacecraft investigated the composition of the ocean by analysis of material ejected into space by the moon’s cryovolcanic plume 4–9 . The analysis of salt-rich ice grains by Cassini’s Cosmic Dust Analyzer ¹⁰ enabled inference of major solutes in the ocean water (...

Results from the Cassini‐Huygens space mission at Enceladus revealed a substantial inventory of organic species embedded in plume and E ring ice grains originating from a global subsurface and putative habitable ocean. Compositional analysis by the Cosmic Dust Analyzer indicated the presence of aromatic species and constrained some structural featu...

Europa and Enceladus, respective moons of Jupiter and Saturn, are prime targets in the exploration of potentially habitable extraterrestrial ocean worlds. Organic material could be incorporated from the ocean into ice grains ejected from the surface or in potential plumes and detected via spacecraft flybys with impact ionization mass spectrometers,...

The coupling of an Orbitrap-based mass analyzer to the laser-induced liquid beam ion desorption (LILBID) technique has been investigated, with the aim to reproduce the mass spectra recorded by Cassini's Cosmic Dust Analyzer (CDA) in the vicinity of Saturn's icy moon Enceladus. LILBID setups are usually coupled with time-of-flight (TOF) mass analyze...

The reliable identification of biosignatures is key to the search for life elsewhere. On ocean worlds like Enceladus or Europa, this can be achieved by impact ionization mass spectrometers, such as the SUrface Dust Analyzer (SUDA) on board NASA's upcoming Europa Clipper mission. During spacecraft flybys, these instruments can sample ice grains form...

Mass spectrometers on board spacecraft typically use either impact ionization or electron ionization (EI) as ion sources. Understanding the similarities and differences in the spectral signatures and fragmentation patterns produced by different techniques in mass spectrometry could elucidate the composition of organic compounds. Here we present a c...

Spaceborne impact ionization mass spectrometers, such as the Cosmic Dust Analyzer on board the past Cassini spacecraft or the SUrface Dust Analyzer being built for NASA's upcoming Europa Clipper mission, are of crucial importance for the exploration of icy moons in the Solar System, such as Saturn's moon Enceladus or Jupiter's moon Europa. For the...

The identification of biosignatures on extraterrestrial ocean worlds is key to the search for life on these bodies. Saturn’s icy moon Enceladus, and possibly Jupiter’s moon Europa, eject plumes containing gas and ice grains formed from subsurface salty water into space [1,2,3,4]. The emitted ice grains can be analyzed by impact ionization mass spec...

Identifying and distinguishing between abiotic and biotic signatures of organic molecules such as amino acids and fatty acids is key to the search for life on extraterrestrial ocean worlds. Impact ionization mass spectrometers can potentially achieve this by sampling water ice grains formed from ocean water and ejected by moons such as Enceladus an...

The icy satellites of Jupiter and Saturn are perhaps the most promising places in the Solar System regarding habitability. However, the potential habitable environments are hidden underneath km-thick ice shells. The discovery of Enceladus’ plume by the Cassini mission has provided vital clues in our understanding of the processes occurring within t...

Reliable identification of biosignatures, such as amino acids, fatty acids, and peptides, on extraterrestrial ocean worlds is a key prerequisite for space missions that search for life or its emergence on these worlds. One promising approach is the use of high-performance in situ impact ionization mass spectrometers to sample water ice grains emerg...

Saturn’s moon Enceladus is erupting a plume of gas and ice grains from its south pole. Linked directly to the moon’s subsurface global ocean, plume material travels through cracks in the icy crust and is ejected into space. The subsurface ocean is believed to be in contact with the rocky core, with ongoing hydrothermal activity present. The Cassini...

Rationale: Detecting ice grains with impact ionization mass spectrometers in space provides information about the compositions of ice grains and their sources. Depending on the impact speeds of the ice grains onto the metal target of a mass spectrometer, ionization conditions can vary substantially, resulting in changes to the appearance of the re...

Saturn's moon Enceladus harbours a global water ocean 1 , which lies under an ice crust and above a rocky core 2 . Through warm cracks in the crust 3 a cryo-volcanic plume ejects ice grains and vapour into space4-7 that contain materials originating from the ocean8,9. Hydrothermal activity is suspected to occur deep inside the porous core10-12, pow...

Pure water ice dominates the composition of the micron and sub-micron sized dust particles in Saturn’s E-ring, a ring constantly replenished by active ice jets of the moon Enceladus [1]. Details about the composition of this tenuous, optically thin ring can only be constrained by in situ measurements. The Cosmic Dust Analyzer (CDA) onboard Cassini...

The Cosmic Dust Analyzer (CDA) aboard the Cassini spacecraft performs in-situ measurements of the chemical composition of icy dust grains impinging onto the target surface. The instrument recorded cationic Time-of-Flight (ToF) mass spectra of organic-bearing ice grains emitted from Enceladus at different impact velocities causing different molecula...

The ice and dust particles ejected into Saturn's E-ring provide direct insight into the composition of Enceladus' sub-surface ocean. This ocean is in contact with the rocky-core and there is evidence for hydrothermal activity [1][2]. Chemical species in the liquid are transported through vents and ejected out of Enceladus in the form of gas and ice...

ENIJA was developed to search for the prebiotic molecules and biogenic key compounds like amino acids in the plumes of Saturn's moon Enceladus. ENIJA records time-of-flight mass spectra in the range between 1 and 2000 u produced by high-velocity impacts of individual grains onto a metal target. The spectrometer has a measurement mode for cations or...