scholarly journals AMBITION – comet nucleus cryogenic sample return

2021 ◽  
Author(s):  
D. Bockelée-Morvan ◽  
Gianrico Filacchione ◽  
Kathrin Altwegg ◽  
Eleonora Bianchi ◽  
Martin Bizzarro ◽  
...  
Keyword(s):  
Giant Planet ◽  
Building Blocks ◽  
Cometary Nucleus ◽  
Comet Nucleus ◽  
Surface Layers ◽  
International Context ◽  
Rosetta Mission ◽  
Nucleus Surface ◽  
And Storage ◽  
Scientific Questions

AbstractWe describe the AMBITION project, a mission to return the first-ever cryogenically-stored sample of a cometary nucleus, that has been proposed for the ESA Science Programme Voyage 2050. Comets are the leftover building blocks of giant planet cores and other planetary bodies, and fingerprints of Solar System’s formation processes. We summarise some of the most important questions still open in cometary science and Solar System formation after the successful Rosetta mission. We show that many of these scientific questions require sample analysis using techniques that are only possible in laboratories on Earth. We summarize measurements, instrumentation and mission scenarios that can address these questions. We emphasize the need for returning a sample collected at depth or, still more challenging, at cryogenic temperatures while preserving the stratigraphy of the comet nucleus surface layers. We provide requirements for the next generation of landers, for cryogenic sample acquisition and storage during the return to Earth. Rendezvous missions to the main belt comets and Centaurs, expanding our knowledge by exploring new classes of comets, are also discussed. The AMBITION project is discussed in the international context of comet and asteroid space exploration.

scholarly journals The Rosetta Mission: Comet and Asteroid Exploration

2009 ◽  
Vol 5 (S263) ◽  
pp. 312-316
Author(s):  
Rita Schulz
Keyword(s):  
Physical Properties ◽  
European Space Agency ◽  
Comet Nucleus ◽  
Asteroid Exploration ◽  
Space Agency ◽  
Rosetta Mission ◽  
Nucleus Surface ◽  
Multi Wavelength ◽  
Rosetta Lander

AbstractIn March 2004 the European Space Agency launched its Planetary Cornerstone Mission Rosetta to rendezvous with Jupiter-family comet 67P/Churyumov-Gerasimenko. The Rosetta mission represents the next step into the improvement of our understanding of comet nuclei naturally following the four successful comet nucleus fly-by missions carried out in the past. It will however not perform a simple fly-by at its target comet, but combines an Orbiter and a Lander Mission. The Rosetta spacecraft will go in orbit around the comet nucleus when it is still far away from the Sun, and escort the comet for more than a year along its pre- and post-perihelion orbit while monitoring the evolution of the nucleus and the coma as a function of increasing and decreasing solar flux input. Different instrumentations will be used in parallel, from multi-wavelength spectrometry to in-situ measurements of coma and nucleus composition and physical properties. In addition the Rosetta Lander Philae will land on the nucleus surface, before the comet is too active to permit such a landing (i.e. at around r = 3 AU) and examine the surface and subsurface composition as well as its physical properties. Two fly-bys at main belt asteroids have been scheduled for the Rosetta spacecraft during its journey to the comet. The first fly-by at E-type asteroid (2867) Steins was already successfully executed in September 2008. The second and main fly-by at asteroid (21) Lutetia is scheduled for July 2010.

Opportunities and Challenges in Converting Existing Natural Gas Infrastructure for Hydrogen Operation

2021 ◽  
Author(s):  
Peter Adam
Keyword(s):  
Hydrogen Production ◽  
Natural Gas ◽  
Energy Transition ◽  
Building Blocks ◽  
Hydrogen Economy ◽  
Storage Network ◽  
The World ◽  
Drive Trains ◽  
Regulatory Bodies ◽  
And Storage

Abstract Hydrogen holds enormous potential in helping the world achieve its decarbonization goals and is set to play a key role in the Energy Transition. However, two central building blocks are needed to make the hydrogen economy a reality: 1) a sufficient source of emissions-free (i.e., blue or green) hydrogen production and 2) a needs-based transportation and storage network that can reliably and cost-effectively supply hydrogen to end-users. Given the high costs associated with developing new transportation infrastructure, many governments, pipeline operators, and regulatory bodies have begun exploring if it is both possible and economical to convert existing natural gas (i.e., methane) infrastructure for hydrogen operation. This paper outlines opportunities and technical challenges associated with such an endeavor – with a particular focus on adaptation requirements for rotating equipment/compressor drive trains and metallurgical and integrity considerations for pipelines.

Tracing the Origins of the Ice Giants through Noble Gas Isotopic Composition

2021 ◽  
Author(s):  
Kathleen Mandt ◽  
Olivier Mousis ◽  
Jonathan Lunine ◽  
Bernard Marty ◽  
Thomas Smith ◽  
...  
Keyword(s):  
Solar System ◽  
Isotopic Composition ◽  
Heavy Element ◽  
Noble Gas ◽  
Giant Planet ◽  
Isotope Ratios ◽  
Building Blocks ◽  
Giant Planets ◽  
Element Abundances ◽  
Current State

<p>The current composition of giant planet atmospheres provides information on how such planets formed, and on the origin of the solid building blocks that contributed to their formation. Noble gas abundances and their isotope ratios are among the most valuable pieces of evidence for tracing the origin of the materials from which the giant planets formed. In this review we first outline the current state of knowledge for heavy element abundances in the giant planets and explain what is currently understood about the reservoirs of icy building blocks that could have contributed to the formation of the Ice Giants. We then outline how noble gas isotope ratios have provided details on the original sources of noble gases in various materials throughout the solar system. We follow this with a discussion on how noble gases are trapped in ice and rock that later became the building blocks for the giant planets and how the heavy element abundances could have been locally enriched in the protosolar nebula. We then provide a review of the current state of knowledge of noble gas abundances and isotope ratios in various solar system reservoirs, and discuss measurements needed to understand the origin of the ice giants. Finally, we outline how formation and interior evolution will influence the noble gas abundances and isotope ratios observed in the ice giants today. Measurements that a future atmospheric probe will need to make include (1) the <sup>3</sup>He/<sup>4</sup>He isotope ratio to help constrain the protosolar D/H and <sup>3</sup>He/<sup>4</sup>He; (2) the <sup>20</sup>Ne/<sup>22</sup>Ne and <sup>21</sup>Ne/<sup>22</sup>Ne to separate primordial noble gas reservoirs similar to the approach used in studying meteorites; (3) the Kr/Ar and Xe/Ar to determine if the building blocks were Jupiter-like or similar to 67P/C-G and Chondrites; (4) the krypton isotope ratios for the first giant planet observations of these isotopes; and (5) the xenon isotopes for comparison with the wide range of values represented by solar system reservoirs.</p><p>Mandt, K. E., Mousis, O., Lunine, J., Marty, B., Smith, T., Luspay-Kuti, A., & Aguichine, A. (2020). Tracing the origins of the ice giants through noble gas isotopic composition. Space Science Reviews, 216(5), 1-37.</p>

Modeling Motion

2011 ◽  
pp. 327-345
Author(s):  
Roy Gelbard ◽  
Israel Spiegler
Keyword(s):  
Basic Problem ◽  
Building Blocks ◽  
Motion Data ◽  
Data Comparison ◽  
Motion System ◽  
Binary Model ◽  
The Common ◽  
Key Frames ◽  
Machine Readable ◽  
And Storage

The research proposes a model for the representation and storage of motion data that enables the communication, storage, and analysis of patterns of motion, as with spoken and written languages. The basic problem is the lack of a machine-readable motion alphabet. We thus set out to define the elemental components and building blocks of motion, coming up with what we call the motion byte as the basis for a motion language that has words, phrases, and sentences. The binary-based model we develop, which is significantly different from the common “key frames” approach, is also a method of storing motion data. Comparison with a standard motion system, based on key frames, indicates a significant advantage for our binary model.

scholarly journals Ice Particle Emission from Cometary Analogues

1991 ◽  
Vol 126 ◽  
pp. 257-260
Author(s):  
H. Kohl ◽  
E. Grün
Keyword(s):  
Cometary Nucleus ◽  
Interplanetary Dust ◽  
Particle Emission ◽  
Dust Particles ◽  
Vacuum System ◽  
Simulation Experiments ◽  
Water Ice ◽  
Mineral Particles ◽  
Nucleus Surface ◽  
Particle Ejection

AbstractDust particles originating from comets are an important constituent of the interplanetary dust regime. In order to study the ejection mechanisms from the cometary nucleus surface simulation experiments in the laboratory have been performed. Samples consisting of water ice, carbon dioxide ice and dust grains have been studied when they are irradiated by artificial sunlight within a cooled vacuum system. It has been shown that particle emission is extremely dependent on the initial composition of the samples. For samples with a distinct amount of non-volatile, mineral particles the formation of a dust mantle and, as a consequence, rapid decrease of particle ejection has been observed.

scholarly journals Determining the origin of the building blocks of the Ice Giants based on analogue measurements from comets

2019 ◽  
Vol 491 (1) ◽  
pp. 488-494 ◽  
Author(s):  
K E Mandt ◽  
O Mousis ◽  
S Treat
Keyword(s):  
Noble Gas ◽  
Giant Planet ◽  
Solid Material ◽  
Building Blocks ◽  
Atmospheric Composition ◽  
Isotopic Ratios ◽  
Carbon And Nitrogen ◽  
Formation Conditions ◽  
Comet 67P

ABSTRACT The abundances of the heavy elements and isotopic ratios in the present atmospheres of the giant planets can be used to trace the composition of volatiles that were present in the icy solid material that contributed to their formation. The first definitive measurements of noble gas abundances and isotope ratios at comet 67P/Churyumov–Gerasimenko (67P/C–G) were recently published by Marty et al. (2017) and Rubin et al. (2018, 2019). The implications of these abundances for the formation conditions of the 67P/C–G building blocks were then evaluated by Mousis et al. (2018a). We add here an analysis of the implications of these results for understanding the formation conditions of the building blocks of the Ice Giants and discuss how future measurements of Ice Giant atmospheric composition can be interpreted. We first evaluate the best approach for comparing comet observations with giant planet composition, and then determine what would be the current composition of the Ice Giant atmospheres based on four potential sources for their building blocks. We provide four scenarios for the origin of the Ice Giants building blocks based on four primary constraints for building block composition: (1) the bulk abundance of carbon relative to nitrogen, (2) noble gas abundances relative to carbon and nitrogen, (3) abundance ratios Kr/Ar and Xe/Ar, and (4) Xe isotopic ratios. In situ measurements of these quantities by a Galileo-like entry probe in the atmosphere(s) of Uranus and/or Neptune should place important constraints on the formation conditions of the Ice Giants.

scholarly journals Post-rendezvous radar properties of comet 67P/CG from the Rosetta Mission: understanding future Earth-based radar observations and the dynamical evolution of comets

2019 ◽  
Vol 489 (2) ◽  
pp. 1667-1683 ◽  
Author(s):  
Essam Heggy ◽  
Elizabeth M Palmer ◽  
Alain Hérique ◽  
Wlodek Kofman ◽  
M Ramy El-Maarry
Keyword(s):  
Large Scale ◽  
Structural Changes ◽  
Dynamical Evolution ◽  
Textural Properties ◽  
Building Blocks ◽  
Cometary Nucleus ◽  
Small Scale ◽  
Small Bodies ◽  
Radar Observations ◽  
Comet 67P

ABSTRACT Radar observations provide crucial insights into the formation and dynamical evolution of comets. This ability is constrained by our knowledge of the dielectric and textural properties of these small-bodies. Using several observations by Rosetta as well as results from the Earth-based Arecibo radio telescope, we provide an updated and comprehensive dielectric and roughness description of Comet 67P/CG, which can provide new constraints on the radar properties of other nuclei. Furthermore, contrary to previous assumptions of cometary surfaces being dielectrically homogeneous and smooth, we find that cometary surfaces are dielectrically heterogeneous ( εr′≈1.6–3.2), and are rough at X- and S-band frequencies, which are widely used in characterization of small-bodies. We also investigate the lack of signal broadening in CONSERT observations through the comet head. Our results suggest that primordial building blocks in the subsurface are either absent, smaller than the radar wavelength, or have a weak dielectric contrast (Δ εr′). To constrain this ambiguity, we use optical albedo measurements by the OSIRIS camera of the freshly exposed subsurface after the Aswan cliff collapse. We find that the hypothetical subsurface blocks should have |Δ εr′|≳0.15, setting an upper limit of ∼ 1 m on the size of 67P/CG's primordial building blocks if they exist. Our analysis is consistent with a purely thermal origin for the ∼ 3 m surface bumps on pit walls and cliff-faces, hypothesized to be high-centred polygons formed from fracturing of the sintered shallow ice-bearing subsurface due to seasonal thermal expansion and contraction. Potential changes in 67P/CG's radar reflectivity at these at X- and S-bands can be associated with large-scale structural changes of the nucleus rather than small-scale textural ones. Monitoring changes in 67P/CG's radar properties during repeated close-approaches via Earth-based observations can constrain the dynamical evolution of its cometary nucleus.

ROSETTA mission: satellite orbits around a cometary nucleus

1998 ◽  
Vol 46 (6-7) ◽  
pp. 649-671 ◽  
Author(s):  
D.J. Scheeres ◽  
F. Marzari ◽  
L. Tomasella ◽  
V. Vanzani
Keyword(s):  
Cometary Nucleus ◽  
Satellite Orbits ◽  
Mission Satellite ◽  
Rosetta Mission

An instrument for in situ comet nucleus surface density profile measurement by gamma ray attenuation

2001 ◽  
Vol 49 (9) ◽  
pp. 961-976 ◽  
Author(s):  
Andrew J. Ball ◽  
Stanislaw Gadomski ◽  
Marek Banaszkiewicz ◽  
Tilman Spohn ◽  
Thomas J. Ahrens ◽  
...  
Keyword(s):  
Density Profile ◽  
Surface Density ◽  
Gamma Ray ◽  
Profile Measurement ◽  
Comet Nucleus ◽  
Nucleus Surface ◽  
Gamma Ray Attenuation

scholarly journals Applying Cryo-X-ray Photoelectron Spectroscopy to Study the Surface Chemical Composition of Fungi and Viruses

2021 ◽  
Vol 9 ◽  
Author(s):  
Andrey Shchukarev ◽  
Emelie Backman ◽  
Samuel Watts ◽  
Stefan Salentinig ◽  
Constantin F. Urban ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Photoelectron Spectroscopy ◽  
Biological Systems ◽  
Building Blocks ◽  
Model Organisms ◽  
Surface Chemical ◽  
Surface Layers ◽  
Xps Spectra ◽  
X Ray ◽  
Surface Chemical Composition

Interaction between microorganisms and their surroundings are generally mediated via the cell wall or cell envelope. An understanding of the overall chemical composition of these surface layers may give clues on how these interactions occur and suggest mechanisms to manipulate them. This knowledge is key, for instance, in research aiming to reduce colonization of medical devices and device-related infections from different types of microorganisms. In this context, X-ray photoelectron spectroscopy (XPS) is a powerful technique as its analysis depth below 10 nm enables studies of the outermost surface structures of microorganism. Of specific interest for the study of biological systems is cryogenic XPS (cryo-XPS). This technique allows studies of intact fast-frozen hydrated samples without the need for pre-treatment procedures that may cause the cell structure to collapse or change due to the loss of water. Previously, cryo-XPS has been applied to study bacterial and algal surfaces with respect to their composition of lipids, polysaccharides and peptide (protein and/or peptidoglycan). This contribution focuses onto two other groups of microorganisms with widely different architecture and modes of life, namely fungi and viruses. It evaluates to what extent existing models for data treatment of XPS spectra can be applied to understand the chemical composition of their very different surface layers. XPS data from model organisms as well as reference substances representing specific building blocks of their surface were collected and are presented. These results aims to guide future analysis of the surface chemical composition of biological systems.

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