Selected ice nanoparticle accelerator hypervelocity impact mass spectrometer (SELINA-HIMS): features and impacts of charged particles.

The selected ice nanoparticle accelerator, SELINA, was used to prepare beams of single ice particles with positive or negative charge. Positively charged particles were prepared from deionized water and 0.05-0.

The DESTINY Dust Analyser - a dust telescope for analysing cosmic dust dynamics and composition.

The DESTINY(Demonstration and Experiment of Space Technology for INterplanetary voYage with Phaethon fLyby and dUst Science) Dust Analyser (DDA) is a state-of-the-art dust telescope for the analysis of cosmic dust particles. As the primary scientific payload of the DESTINY mission, it serves the purpose of characterizing the dust environment within the Earth-Moon system, investigating interplanetary and interstellar dust populations at 1 AU from the Sun and studying the dust cloud enveloping the asteroid (3200) Phaethon. DDA features a two-axis pointing platform for increasing the accessible fraction of the sky.

How to identify cell material in a single ice grain emitted from Enceladus or Europa.

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 organic material in high concentrations.

Detection of phosphates originating from Enceladus's ocean.

Saturn's moon Enceladus harbours a global ice-covered water ocean. The Cassini spacecraft investigated the composition of the ocean by analysis of material ejected into space by the moon's cryovolcanic plume. The analysis of salt-rich ice grains by Cassini's Cosmic Dust Analyzer enabled inference of major solutes in the ocean water (Na, K, Cl, HCO, CO) and its alkaline pH.

Discriminating Abiotic and Biotic Fingerprints of Amino Acids and Fatty Acids in Ice Grains Relevant to Ocean Worlds.

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 and Europa, thereby exploring the habitability of their subsurface oceans in spacecraft flybys. Here, we extend previous high-sensitivity laser-based analog experiments of biomolecules in pure water to investigate the mass spectra of amino acids and fatty acids at simulated abiotic and biotic relative abundances.

Analogue spectra for impact ionization mass spectra of water ice grains obtained at different impact speeds in space.

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 resulting mass spectra.

Methods: Here we accurately reproduce mass spectra of water ice grains, recorded with the Cosmic Dust Analyzer (CDA) on board the Cassini spacecraft at typical impact speeds ranging between 4 km/s to 21 km/s, with a laboratory analogue experiment.

In situ collection of dust grains falling from Saturn's rings into its atmosphere.

Saturn's main rings are composed of >95% water ice, and the nature of the remaining few percent has remained unclear. The Cassini spacecraft's traversals between Saturn and its innermost D ring allowed its cosmic dust analyzer (CDA) to collect material released from the main rings and to characterize the ring material infall into Saturn. We report the direct in situ detection of material from Saturn's dense rings by the CDA impact mass spectrometer.

Macromolecular organic compounds from the depths of Enceladus.

Saturn's moon Enceladus harbours a global water ocean , which lies under an ice crust and above a rocky core . Through warm cracks in the crust a cryo-volcanic plume ejects ice grains and vapour into space that contain materials originating from the ocean. Hydrothermal activity is suspected to occur deep inside the porous core, powered by tidal dissipation .

New experimental capability to investigate the hypervelocity micrometeoroid bombardment of cryogenic surfaces.

Ice is prevalent throughout the solar system and beyond. Though the evolution of many of these icy surfaces is highly dependent on associated micrometeoroid impact phenomena, experimental investigation of these impacts has been extremely limited, especially at the impactor speeds encountered in space. The dust accelerator facility at the Institute for Modeling Plasmas, Atmospheres, and Cosmic Dust (IMPACT) of NASA's Solar System Exploration Research Virtual Institute has developed a novel cryogenic system that will facilitate future study of hypervelocity impacts into ice and icy regolith.

Ongoing hydrothermal activities within Enceladus.

Detection of sodium-salt-rich ice grains emitted from the plume of the Saturnian moon Enceladus suggests that the grains formed as frozen droplets from a liquid water reservoir that is, or has been, in contact with rock. Gravitational field measurements suggest a regional south polar subsurface ocean of about 10 kilometres thickness located beneath an ice crust 30 to 40 kilometres thick. These findings imply rock-water interactions in regions surrounding the core of Enceladus.

3 MV hypervelocity dust accelerator at the Colorado Center for Lunar Dust and Atmospheric Studies.

A hypervelocity dust accelerator for studying micrometeorite impacts has been constructed at the Colorado Center for Lunar Dust and Atmospheric Studies (CCLDAS) at the University of Colorado. Based on the Max-Planck-Institüt für Kernphysik (MPI-K) accelerator, this accelerator is capable of emitting single particles of a specific mass and velocity selected by the user. The accelerator consists of a 3 MV Pelletron generator with a dust source, four image charge pickup detectors, and two interchangeable target chambers: a large high-vacuum test bed and an ultra-high vacuum impact study chamber.

A 2 MV Van de Graaff accelerator as a tool for planetary and impact physics research.

Investigating the dynamical and physical properties of cosmic dust can reveal a great deal of information about both the dust and its many sources. Over recent years, several spacecraft (e.g.

Mass spectrometry of hyper-velocity impacts of organic micrograins.

The study of hyper-velocity impacts of micrometeoroids is important for the calibration of dust sensors in space applications. For this purpose, submicron-sized synthetic dust grains comprising either polystyrene or poly[bis(4-vinylthiophenyl)sulfide] were coated with an ultrathin overlayer of an electrically conductive organic polymer (either polypyrrole or polyaniline) and were accelerated to speeds between 3 and 35 km s(-1) using the Heidelberg Dust Accelerator facility. Time-of-flight mass spectrometry was applied to analyse the resulting ionic impact plasma using a newly developed Large Area Mass Analyser (LAMA).

Characteristics of a dust trajectory sensor.

Trajectories of cosmic dust particles are determined by the measurement of the electrical signals that are induced when a charged grain flies through a position-sensitive electrode system. A typical dust trajectory sensor has four sensor planes consisting of about 16 wire electrodes each. Two adjacent planes have orthogonal wire directions.

Slow dust in Enceladus' plume from condensation and wall collisions in tiger stripe fractures.

One of the spectacular discoveries of the Cassini spacecraft was the plume of water vapour and icy particles (dust) originating near the south pole of Saturn's moon Enceladus. The data imply considerably smaller velocities for the grains than for the vapour, which has been difficult to understand. The gas and dust are too dilute in the plume to interact, so the difference must arise below the surface.

The source of Saturn's G ring.

The origin of Saturn's narrow G ring has been unclear. We show that it contains a bright arc located 167,495.6 +/- 1.

Cassini dust measurements at Enceladus and implications for the origin of the E ring.

During Cassini's close flyby of Enceladus on 14 July 2005, the High Rate Detector of the Cosmic Dust Analyzer registered micron-sized dust particles enveloping this satellite. The dust impact rate peaked about 1 minute before the closest approach of the spacecraft to the moon. This asymmetric signature is consistent with a locally enhanced dust production in the south polar region of Enceladus.

Composition of saturnian stream particles.

During Cassini's approach to Saturn, the Cosmic Dust Analyser (CDA) discovered streams of tiny (less than 20 nanometers) high-velocity (approximately 100 kilometers per second) dust particles escaping from the saturnian system. A fraction of these impactors originated from the outskirts of Saturn's dense A ring. The CDA time-of-flight mass spectrometer recorded 584 mass spectra from the stream particles.

High-velocity streams of dust originating from Saturn.

High-velocity submicrometre-sized dust particles expelled from the jovian system have been identified by dust detectors on board several spacecraft. On the basis of periodicities in the dust impact rate, Jupiter's moon Io was found to be the dominant source of the streams. The grains become positively charged within the plasma environment of Jupiter's magnetosphere, and gain energy from its co-rotational electric field.