Anna Butterworth

Anna Butterworth
University of California, Berkeley | UCB · Space Sciences Laboratory

PhD

About

148
Publications
9,976
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4,018
Citations
Additional affiliations
June 2003 - present
University of California, Berkeley
Position
  • Research Assistant
September 1998 - May 2003
The Open University (UK)
Position
  • PostDoc Position

Publications

Publications (148)
Article
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Significance The search for organic biosignatures indicative of life elsewhere in our solar system is an exciting quest that, if successful, will have a profound impact on our biological uniqueness. Saturn’s icy moon Enceladus is a promising location for a second occurrence of life due to its salty subsurface ocean. Plumes that jet out through the...
Preprint
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NASA's Stardust mission utilized a sample collector composed of aerogel and aluminum foil to return cometary and interstellar particles to Earth. Analysis of the aluminum foil begins with locating craters produced by hypervelocity impacts of cometary and interstellar dust. Interstellar dust craters are typically less than one micrometer in size and...
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Enceladus is a prime candidate in the solar system for in-depth astrobiological studies searching for habitability and life because it has a liquid water ocean with significant organic content and ongoing cryovolcanic activity. The presence of ice plumes that jet up through fissures in the ice crust covering the sub-surface ocean, enables remote sa...
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Enceladus is a compelling destination for astrobiological analyses due to the presence of simple and complex organic constituents in cryovolcanic plumes that jet from its subsurface ocean. Enceladus plume capture during a flyby or orbiter mission is an appealing method for obtaining pristine ocean samples for scientific studies of this organic cont...
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Microfabricated glass microfluidic and Capillary Electrophoresis (CE) devices have been utilized in a wide variety of applications over the past thirty years. At the Berkeley Space Sciences Laboratory, we are working to further expand this technology by developing analytical instruments to chemically explore our solar system. This effort requires i...
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The presence and accessibility of a sub‐ice‐surface saline ocean at Enceladus, together with geothermal activity and a rocky core, make it a compelling location to conduct further, in‐depth, astrobiological investigations to probe for organic molecules indicative of extraterrestrial life. Cryovolcanic plumes in the south polar region of Enceladus e...
Article
STEM/EDS Tomography of Cometary Dust - Volume 25 Supplement - Zack Gainsforth, Peter Ercius, Karen Bustillo, Anna L. Butterworth, Christine E. Jilly-Rehak, Andrew J. Westphal
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XAS Between the Stars - Volume 25 Supplement - Zack Gainsforth, Anna L. Butterworth, John A. Tomsick, Andrew J. Westphal
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In a consortium analysis of a large particle captured from the coma of comet 81P/Wild 2 by the Stardust spacecraft, we report the discovery of a field of fine‐grained material (FGM) in contact with a large sulfide particle. The FGM was partially located in an embayment in the sulfide. As a consequence, some of the FGM appears to have been protected...
Article
The relative fractions of Fe in metal, sulfide, or oxide - the Fe oxidation state - in the interstellar medium (ISM) can provide constraints on the processes that operated on material in the protosolar disk. We used synchrotron-based X-ray absorption spectra of three mineral standards and two kinds of primitive extraterrestrial materials to constra...
Preprint
Full-text available
In a consortium analysis of a large particle captured from the coma of comet 81P/Wild 2 by the Stardust spacecraft, we report the discovery of a field of fine-grained material (FGM) in contact with a large sulfide particle. The FGM was partially located in an embayment in the sulfide, so appears to have been largely protected from damage during hyp...
Preprint
Full-text available
The oxidation state of iron in the interstellar medium (ISM) can provide constraints on the processes that operated on material in the protosolar disk. We used synchrotron-based X-ray absorption spectra of several mineral standards and two kinds of primitive extraterrestrial materials to constrain the oxidation state and mineralogy of the host-phas...
Article
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Enceladus presents an excellent opportunity to detect organic molecules that are relevant for habitability as well as bioorganic molecules that provide evidence for extraterrestrial life because Enceladus' plume is composed of material from the subsurface ocean that has a high habitability potential and significant organic content. A primary challe...
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Lauretta (2005) produced sulfide in the laboratory by exposing canonical nebular metal analogs to H2S gas under temperatures and pressures relevant to the formation of the Solar System. The resulting reactions produced a suite of sulfides and nanophase materials not visible at the microprobe scale, but which we have now analyzed by TEM for comparis...
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The mineralogy of comet 81P/Wild 2 particles, collected in aerogel by the Stardust mission, has been determined using synchrotron Fe-K X-ray absorption spectroscopy with in situ transmission XRD and X-ray fluorescence, plus complementary microRaman analyses. Our investigation focuses on the terminal grains of eight Stardust tracks: C2112,4,170,0,0;...
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Atomic Layer Deposition (ALD) is a scalable deposition technique known for producing uniform, conformal films of a wide range of compounds on nearly any substrate material. These traits make it an ideal deposition method for producing films to replace the National Institute of Standards and Technology (NIST) standards and create Standard Reference...
Article
Recent observations indicate that >99% of the small bodies in the Solar System reside in its outer reaches --- in the Kuiper Belt and Oort Cloud. Kuiper Belt bodies are probably the best preserved representatives of the icy planetesimals that dominated the bulk of the solid mass in the early Solar System. They likely contain preserved materials inh...
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Using chemical and petrologic evidence and modeling, we deduce that two chondrule-like particles named Iris and Callie, from Stardust cometary track C2052,12,74, formed in an environment very similar to that seen for type II chondrules in meteorites. Iris was heated near liquidus, equilibrated, and cooled at ≤100 °C h-1 and within ≈2 log units of t...
Article
Individual particles from comet 81P/Wild 2 collected by NASA’s Stardust mission vary in size from small sub-μm fragments found in the walls of the aerogel tracks, to large fragments up to tens of μm in size found towards the termini of tracks. The comet, in an orbit beyond Neptune since its formation, retains an intact a record of early-Solar-Syste...
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A novel design for a flight-ready integrated microfluidic processor comprising capillary electrophoresis and laser fluorescence detection of organic molecules.
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We measured metal content of a giant cluster IDP, and show that collection biases do not explain the difference in metal content between CP-IDPs and Wild 2.
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The NASA Stardust mission used silica aerogel slabs to slowly decelerate and capture impinging cosmic dust particles for return to Earth. During this process, impact tracks are generated along the trajectory of the particle into the aerogel. It is believed that the morphology and dimensions of these tracks, together with the state of captured grain...
Article
Hard X-ray, quantitative, fluorescence elemental imaging was performed on the ID22NI nanoprobe and ID22 microprobe beam lines of the European Synchrotron Research facility (ESRF) in Grenoble, France, on eight interstellar candidate impact features in the framework of the NASA Stardust Interstellar Preliminary Examination (ISPE). Three features were...
Article
With the discovery of bona fide extraterrestrial materials in the Stardust Interstellar Dust Collector, NASA now has a fundamentally new returned sample collection, after the Apollo, Antarctic meteorite, Cosmic Dust, Genesis, Stardust Cometary, Hayabusa, and Exposed Space Hardware samples. Here, and in companion papers in this volume, we present th...
Article
Here, we report the identification of 69 tracks in approximately 250 cm2 of aerogel collectors of the Stardust Interstellar Dust Collector. We identified these tracks through Stardust@home, a distributed internet-based virtual microscope and search engine, in which > 30,000 amateur scientists collectively performed >9 9 107 searches on approximatel...
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We report the quantitative characterization by synchrotron soft X-ray spectroscopy of 31 potential impact features in the aerogel capture medium of the Stardust Interstellar Dust Collector. Samples were analyzed in aerogel by acquiring high spatial resolution maps and high energy-resolution spectra of major rock-forming elements Mg, Al, Si, Fe, and...
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We discuss the inherent difficulties that arise during "ground truth" characterization of the Stardust interstellar dust collector. The challenge of identifying contemporary interstellar dust impact tracks in aerogel is described within the context of background spacecraft secondaries and possible interplanetary dust particles and beta-meteoroids....
Article
Under the auspices of the Stardust Interstellar Preliminary Examination, picokeystones extracted from the Stardust Interstellar Dust Collector were examined with synchrotron Fourier transform infrared (FTIR) microscopy to establish whether they contained extraterrestrial organic material. The picokeystones were found to be contaminated with varying...
Article
Here, we report analyses by synchrotron X-ray fluorescence microscopy of the elemental composition of eight candidate impact features extracted from the Stardust Interstellar Dust Collector (SIDC). Six of the features were unambiguous tracks, and two were crater-like features. Five of the tracks are so-called "midnight" tracks-that is, they had tra...
Article
The NASA Stardust spacecraft exposed an aerogel collector to the interstellar dust passing through the solar system. We performed X-ray fluorescence element mapping and abundance measurements, for elements 19 <= Z <= 30, on six "interstellar candidates," potential interstellar impacts identified by Stardust@Home and extracted for analyses in picoke...
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On the basis of an interstellar dust model compatible with Ulysses and Galileo observations, we calculate and predict the trajectories of interstellar dust (ISD) in the solar system and the distribution of the impact speeds, directions, and flux of ISD particles on the Stardust Interstellar Dust Collector during the two collection periods of the mi...
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The Stardust Interstellar Preliminary Examination team analyzed thirteen Al foils from the NASA Stardust interstellar collector tray in order to locate candidate interstellar dust (ISD) grain impacts. Scanning electron microscope (SEM) images reveal that the foils possess abundant impact crater and crater-like features. Elemental analyses of the cr...
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Seven particles captured by the Stardust Interstellar Dust Collector and returned to Earth for laboratory analysis have features consistent with an origin in the contemporary interstellar dust stream. More than 50 spacecraft debris particles were also identified. The interstellar dust candidates are readily distinguished from debris impacts on the...
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Condensation via troilite to pyrrhotite and other mechanisms are considered for a Ni-zoned pyrrhotite from a Stardust grain to understand its origin.
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We report the presence of preserved primitive fine-grained material containing an enstatite whisker with the crystallographic characteristics of a primary condensate in a sample of the Jupiter-family comet Wild 2, returned to earth by NASAʼs Stardust mission. The preserved primitive material is composed of silica-rich amorphous material embedded wi...
Article
The Mars 2020 Mission leverages Mars Science Laboratory Curiosity rover heritage to perform an investigation on Mars with objectives including: (A) Determine environmental habitability, search for regions and materials with high biosignature preservation potential, and search for evidence of past life, and (B) Scientifically select and cache well c...
Article
The oxidation state of transition metal elements is an indicator of the environmental conditions during formation and history of extraterrestrial materials. We studied the iron valence state of fine-grained material from a bulbous track extracted from the Stardust cometary collector. It likely originated from primitive material of the comet Wild 2....
Article
Using synchrotron-based X-ray diffraction measurements, we identified crystalline material in two particles of extraterrestrial origin extracted from the Stardust Interstellar Dust Collector. The first particle, I1047,1,34 (Hylabrook), consisted of a mosaiced olivine grain approximately 1 mu m in size with internal strain fields up to 0.3%. The uni...
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We present a summary of mineralogical and isotopic analyses of coarse- and fine-grained particles in Stardust Track C2052,2,74.
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NanoFTIR is a new technique to probe infrared modes below the diffraction limit of FTIR. We apply it here to examine an amorphous Stardust silicate.
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We report the discovery of preserved primitive fine-grained material from Comet 81P/Wild 2. It is composed of silica-rich amorphous matrix embedded with iron sulfides and silicates. An enstatite whisker is identified inside the matrix.
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We present the results of laboratory campaigns investigating the effects of particle density and composition on the dimensions of tracks created by hypervelocity dust grains hitting Stardust flight spare aerogel collectors.
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Quantification of synchrotron XRF analyses is typically done through comparisons with measurements on the NIST SRM 1832/1833 thin film standards. Unfortunately, these standards are inhomogeneous on small scales at the tens of percent level. We are synthesizing new homogeneous multilayer standards using the Atomic Layer Deposition technique and char...
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We characterize the Fe valence state distribution of the GEMS-like material and combine the results with TEM characterization to better understand the chemical modifications during capture versus the primary nature of the Wild 2 fine-grained material.
Article
We report the discovery of preserved primitive fine-grained material from Comet 81P/Wild 2. It is composed of silica-rich amorphous matrix embedded with iron sulfides and silicates. An enstatite whisker is identified inside the matrix.
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We report S-isotopic measurements (^32S, ^33S, ^34S, ^36S) of a pyrrhotite grain from Comet Wild 2 returned by NASA's Stardust mission.
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We report the petrology, O isotopic composition, and Al-Mg isotope systematics of a chondrule fragment from the Jupiter-family comet Wild 2, returned to Earth by NASA's Stardust mission. This object shows characteristics of a type II chondrule that formed from an evolved oxygen isotopic reservoir. No evidence for extinct 26Al was found, with (26Al/...
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Introduction: In 2000 and 2002 the Stardust Mission exposed aerogel collector panels for a total of about 200 days to the stream of interstellar grains sweeping through the solar system [1]. The material was brought back to Earth in 2006. The goal of this work is the laboratory calibration of the collection process by shooting high speed [5 -30km/s...
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Special Issue: 74th Annual Meeting of the Meteoritical Society, August 8-12, 2011, London, U.K.
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The Stardust Discovery mission returned two unprecedented extraterrestrial samples to terrestrial laboratories: the first samples from a known planetary body beyond the Moon, the Jupiter-family comet 81P/Wild2, and the first sample of contemporary interstellar dust. The Stardust Interstellar Dust Collector is a 0.1m2 array of aerogel and aluminum f...
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of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 – August 5, 2010.
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The fragile structure of chondritic-porous interplanetary dust particles (CP-IDPs) and their minimal parent-body alteration have led researchers to believe these particles originate in comets rather than asteroids where aqueous and thermal alterations have occurred. The solar elemental abundances and atmospheric entry speed of CP-IDPs also suggest...