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The Cosmic Dust Analyzer (CDA) is designed to characterize the dust envirenment in interplanetary space, in the Jovian and in the Saturnian systems. The instrument consists of two major components, the Dust Analyzer (DA) and the HIgh Rate Detector(HRD).
Cosmic dust particle properties obtained from Aerobee rocket measurements
Sensors used in cosmic dust experiments studied for response to microparticle hypervelocity impacts, noting relationship to velocity
A discussion of cosmic dust, its classification, the usefulness of its analysis, and problems associated with its analysis is presented. All measurements on stratospheric dust particles presented here were made with secondary ion mass spectrometry (SIMS). The SIMS technique turns out to be an extremely useful tool in the study of very small particles and made a number of firsts possible. The isotopic composition of cosmic dust particles were measured for the first time. It was also the first time that it was possible to measure the abundances of the rare earth elements in these particles. However, the most important advance this work represents is that both trace elemental and isotopic abundances were successfully measured in the same particles. Thus, for the first time, it is possible to compare isotopic and trace element abundance data of the same cosmic dust particles.
High altitude balloon top collections of cosmic dust shows evidence of absence of crystal structure in particles
High altitude balloon top collections of cosmic dust shows evidence of absence of crystal structure in particles
Pioneer 8 and 9 measured cosmic dust flux rate data are in agreement with astronomy theory, zodiacal light measurements, and ground-based observations, but differ markedly from the high flux rates deduced from earlier in situ measurements. As many as seven orders-of-magnitude separate the small particle end of the high and low flux curves. It was concluded that the data from the multicoincidence cosmic dust sensors have not only measured very low flux for micrometeorites, which is in keeping with astronomy theory, but have also shown how a high flux theory may be based on faulty data.
The study of cosmic dust can provide useful data in the investigation of the origin of the Earth and the evolution of celestial bodies. Three types of cosmic dust (ferriginous, siliceous, and glassy) were discovered in the seafloor sediments near China. Their chemical composition and microstructure were examined by X-ray diffraction, fractography, and electron microscopy. The major mineral in an iron-containing cosmic dust is magnetite. The silicate spheres contain sundry metals and metal oxides. Glassy microtektites are similar in composition to tektites, and are found in all the major meteorite areas worldwide.
Studies of cosmic dust particles collected at altitudes of 80 to 120 km over White Sands, New Mexico, and at times of noctilucent clouds over Kiruna, Sweden, indicate that an anomalously high atomic weight contribution is present within those particles collected at Kiruna. The elements observed are inconsistent with an origin due to atomic bomb fallout, meteoroidal crumbling, lunar ejecta, or comets. Many of these heavy elements may be stable in particulate form at the relatively high temperatures found in the coolest regions of the solar atmosphere. Some implications of the sun as the source of a significant component of cosmic dust are discussed.
Sensors used in cosmic dust experiments studied for response to microparticle hypervelocity impacts, noting relationship to velocity
Sounding rockets sampling of cosmic dust in upper atmosphere during and after Zeta Perseid and Arietid meteor showers
The Cosmic Dust Analyzer (CDA) is designed to characterize the dust environment in interplanetary space, in the Jovian and in the Saturnian systems. The instrument consists of two major components, the Dust Analyzer (DA) and the High Rate Detector (HRD). The DA has a large aperture to provide a large cross section for detection in low flux environments. The DA has the capability of determining dust particle mass, velocity, flight direction, charge, and chemical composition. The chemical composition is determined by the Chemical Analyzer system based on a time-of-flight mass spectrometer. The DA is capable of making full measurements up to one impact/second. The HRD contains two smaller PVDF detectors and electronics designed to characterize dust particle masses at impact rates up to 10(exp 4) impacts/second. These high impact rates are expected during Saturn ring, plane crossings.
A three-axis cosmic dust experiment placed on the lunar surface by the Apollo 17 crew is registering impact parameters of cosmic dust and lunar ejecta. A total of 1117 events have been recorded in eight months of data. Preliminary conclusions on the nature of the data include possible evidence of lunar soil transport associated with the terminators. Particle fluxes have been derived for two of the three sensor systems and for specified conditions of exposure.
Study of the nature of cosmic dust particles collected by two recoverable rockets launched at Fort Churchill, Canada, in the spring of 1970, before the noctilucent cloud season in order to avoid the interference of uplifted atmospheric aerosols during the determination of the concentration of background cosmic dust. The study was designed to verify the results of a previous study for which dust particles were collected in the summer of 1968 by a rocket launched through a noctilucent cloud at the same location. The findings support the hypothesis that occasional high concentrations of dust in the mesosphere are due to uplifted aerosols which could be of a terrestrial or cosmic origin.
The NASA Cosmic Dust Collections includes a collection of interplanetary particles gathered using high-altitude aircraft (the Aircraft Collected Particle collection, or ACP). These particles include cosmic-origin particles as well as particles of terrestrial origin such as volcanic ash, solid rocket motor effluent, and terrestrial dust. The cosmic-origin dust comes from two principal sources - material originating from the diffuse interplanetary background which are uncoupled from the orbits of larger bodies, and cometary-origin particles which are dynamically coupled with the orbits of their parent bodies to form dust streams. These dust stream particles generate short-lived, annual meteor showers and are important because, if they can be identified as originating from a given dust stream, they can be studied in the laboratory as samples of a specific comet. Collecting these particles requires dedicated ACP flights which are timed to coincide with a specific meteor shower. These “timed collections” hold the promise of providing samples from a suite of comets including those never visited by spacecraft [1-3]. This abstract describes a recent (Dec 2020) timed collection attempt, lists previous timed collections with collected particles available for request from the NASA Cosmic Dust Collections, as well as listing ACP collectors which were collected when no meteor showers were active for potential use as control samples.
Cosmic dust may be serious radiation hazard to man and electronic equipment caught in its path. Dust detector uses two operational amplifiers and offers narrower areas for collection of cosmic dust. Detector provides excellent resolution as result of which recording of particle velocities as well as positions of their impact are more accurately determined.
We analyzed data recorded by the Cosmic Dust Analyzer on board the Cassini spacecraft during Enceladus dust plume traversals. Our focus was on profiles of relative abundances of grains of different compositional types derived from mass spectra recorded with the Dust Analyzer subsystem during the Cassini flybys E5 and E17. The E5 profile, corresponding to a steep and fast traversal of the plume, has already been analyzed. In this paper, we included a second profile from the E17 flyby involving a nearly horizontal traversal of the south polar terrain at a significantly lower velocity. Additionally, we incorporated dust detection rates from the High Rate Detector subsystem during flybys E7 and E21. We derived grain size ranges in the different observational data sets and used these data to constrain parameters for a new dust plume model. This model was constructed using a mathematical description of dust ejection implemented in the software package DUDI. Further constraints included published velocities of gas ejection, positions of gas and dust jets, and the mass production rate of the plume. Our model employs two different types of sources: diffuse sources of dust ejected with a lower velocity and jets with a faster and more colimated emission. From our model, we derived dust mass production rates for different compositional grain types, amounting to at least 28 kg s –1 . Previously, salt-rich dust was believed to dominate the plume mass based on E5 data alone. The E17 profile shows a dominance of organic-enriched grains over the south polar terrain, a region not well constrained by E5 data. By including both E5 and E17 profiles, we find the salt-rich dust contribution to be at most 1% by mass. This revision also results from an improved understanding of grain masses of various compositional types that implies smaller sizes for salt-rich grains. Our new model can predict grain numbers and masses for future mission detectors during plume traversals.
Two proposed NASA exobiology flight experiments are described in terms of the approaches to cosmic dust collection and the issues addressed by the analysis of the samples. A passive collector is planned for use with the Cosmic Dust Collection Facility, and an active system is described for attachment to the Space Station Freedom payload. Exobiological study of cosmic dust could provide insights on organic chemistry in the grains and on the relative abundances of biogenic elements in interstellar, cometary, and meteoric samples.