Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Solar System”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 829 records · Page 46
All sourcesNASA NTRSDOE OSTI
NASA NTRS1983

Solar system ice - Amorphous or crystalline?

The meteoritic bombardment of icy surfaces is discussed, focusing on the formation of amorphous ice and its thermal, mechanical, and optical properties. A numerical code has been developed for evaluating the ratio of the volume of the melted and vaporized ice target to the volume of the projectile that has impacted the surface and left a crater. However, water will only vaporize with impact speeds over 4 to 6 km/sec, and subsequent condensation into ice below 150 K will produce amorphous ice. A denser form of amorphous ice exists below 10 K, with the transition into a crystalline form occurring above 150 K. Maximum impact velocities have been defined for all major bodies in the solar system, with the finding that crystalline ice will form in the crater while amorphous ice will form on the ejecta. The amount of each is dependent on the ratio of solidified water to condensed water vapor and on the fraction of solid ejecta.

Smoluchowski, R.↗
NASA NTRS1990

Monodeuterated methane in the outer solar system. IV - Its detection and abundance on Neptune

The 3nu2 band of CH3D was detected in the spectrum of Neptune near 1.6 micron recorded at a spectral resolution of 4/cm with the Cassegrain Fourier Transportation Spectrometer at the 3.6 m Canada-France-Hawaii Telescope CFHT) on Mauna Kea. The analysis of this spectrum, using spectral synthesis techniques, yielded a CH3D/CH4 ratio of about 0.0006, which corresponds to a global D/H ratio for Neptune of about 0.00012, if CH3D is in isotopic fractionation equilibrium with HD. This value is about an order of magnitude larger than an earlier estimate by Orton et al. (1987) based on deconvolution measurements of unresolved molecular emission in the 8-10-micron region. Comparison of this new determination with previous studies of CH3D in the outer solar system shows that, as in the case of Uranus, the D/H on Neptune is strongly enhanced over that found on Jupiter and Saturn and is comparable to the D/H in methane on Titan and in terrestrial methane and water.

De Bergh, C.↗
DOE OSTI2022

Ryugu's nucleosynthetic heritage from the outskirts of the Solar System

Little is known about the origin of the spectral diversity of asteroids and what it says about conditions in the protoplanetary disk. Here we show that samples returned from Cb­type asteroid Ryugu have Fe isotopic anomalies indistinguishable from Ivuna­type (CI) chondrites, which are distinct from all other carbonaceous chondrites. Iron isotopes, therefore, demonstrate that Ryugu and CI chondrites formed in a reservoir that was different from the source regions of other carbonaceous asteroids. Growth and migration of the giant planets destabilized nearby planetesimals and ejected some inwards to be implanted into the Main Belt. In this framework, most carbonaceous chondrites may have originated from regions around the birthplaces of Jupiter and Saturn, while the distinct isotopic composition of CI chondrites and Ryugu may reflect their formation further away in the disk, owing their presence in the inner Solar System to excitation by Uranus and Neptune

58 GEOSCIENCES↗
NASA NTRS2003

The NASA IRTF: Solar System Observations and Mission Support

This report covers the period from 1 July 2002 through 30 June 2003. The NASA Infrared Telescope Facility (IRTF) is a 3.0 m infrared telescope located at an altitude of 4.2 km on the summit of Mauna Kea in Hawaii. It was established by NASA in 1979 primarily to provide infrared observations in support of NASA's programs. The IRTF is managed and operated by the University of Hawaii (UH) Institute for Astronomy (IfA) under a five-year cooperative agreement between NASA and UH that started in February 2001. NASA provides the costs of operation, and NSF provides support for new focal plane instrumentation based on grant applications from IRTF support astronomers. Observing time is open to the entire astronomical community, and 50% of the IRTF observing time is reserved for studies of solar system objects.

Kudritzki, Rolf-Peter↗
NASA NTRS2010

Views from EPOXI. Colors in Our Solar System as an Analog for Extrasolar Planets

With extrasolar planet detection becoming more common place, the frontiers of extrasolar planet science have moved beyond detection to the observations required to determine planetary properties. Once the existing observational challenges have been overcome, the first visible-light studies of extrasolar Earth-sized planets will likely employ filter photometry or low-resolution. spectroscopy to observe disk-integrated radiation from the unresolved planet. While spectroscopy of these targets is highly desirable, and provides the most robust form of characterization. S/N considerations presently limit spectroscopic measurements of extrasolar worlds. Broadband filter photometry will thus serve as a first line of characterization. In this paper we use Extrasolar Observation and Characterization (EPOCh) filter photometry of the Earth. Moon and Mars model spectra. and previous photometric and spectroscopic observations of a range the solar system planets. Titan, and Moon to explore the limitations of using color as a baseline for understanding extrasolar planets

Crow, Carolyn A.↗
NASA NTRS2017

Ion Microprobe Measurements of Comet Dust and Implications for Models of Oxygen Isotope Heterogeneity in the Solar System

The oxygen isotopic compositions of anhydrous minerals in carbonaceous chondrites reflect mixing between a O-16-rich and O-17, O18-rich reservoir. The UV photodissociation of CO (i.e. selfshielding) has been proposed as a mass-independent mechanism for producing these isotopically distinct reservoirs. Self-shielding models predict the composition for the CO gas reservoir to be O-16-rich, and that the accreting primordial dust was in isotopic equilibrium with the gaseous reservoir [1, 2]. Self-shielding also predicts that cometary water, presumed to represent the O-17, O-18-rich reservoir, should be enriched in O-17 and O-18, with compositions of 200 -1000per mille, and that the interaction with this O-17, O-18-rich H2O reservoir altered the compositions of the primordial dust toward planetary values. The bulk composition of the solar nebula, which may be an approximation to the 16O-rich gaseous reservoir, has been constrained by the Genesis results [3]. However, material representing the O-17, O-18-rich end-member is rare [4], and dust representing the original accreting primordial dust has been challenging to conclusively identify in current collections. Anhydrous dust from comets, which accreted in the distal cold regions of the nebula at temperatures below approximately 30K, may provide the best opportunity to measure the oxygen isotope composition of primordial dust. Chondritic porous interplanetary dust particles (CP-IDPs) have been suggested as having cometary origins [5]; however, until direct comparisons with dust from a known comet parent body were made, link between CP-IDPs and comets remained circumstantial. Oxygen isotope analyses of particles from comet 81P/Wild 2 collected by NASA's Stardust mission have revealed surprising similarities to minerals in carbonaceous chondrites which have been interpreted as evidence for large scale radial migration of dust components from the inner solar nebula to the accretion regions of Jupiter- family comets [6]. These studies have been largely focused on the coarse-grained terminal particles extracted from aerogel collectors; hypervelocity capture into aerogel resulted in fine-grained material that was melted and intimately mixed with the SiO2 capture medium. Hypervelocity impacts into Al foils surrounding the aerogel tiles produced impact craters that captured material from the impactor without significant oxygen contamination, allowing for analysis of both the coarse and fine-grained components of the Wild 2 dust. To date, no particles with definitive hydrated mineralogy have been observed in Stardust samples, though this may be a result of alteration due to hypervelocity capture. High-carbon hydrated CS-IDPs have been suggested as resulting from the aqueous alteration of CP-IDPs [7], and may retain evidence for interaction with O-17, O-18-enriched "cometary" water predicted by CO self-shielding. Here we present results of oxygen isotope measurements of twelve Stardust foil craters and four C-rich hydrated IDPs [8, 9], and discuss implications for models of oxygen isotope heterogeneity in the early solar system.

Snead, C. J.↗
NASA NTRS2012

Exploring Earth and the Solar System: Educational Outreach Through NASA's Space Place, SciJinks, and Climate Kids Websites

NASA's Space Place team publishes engaging content and creates an effective environment to inspire a young audience to dare mighty things. NASA uses the Space Place, Climate Kids, and SciJinks websites to cultivate interest among elementary-school-aged children in both science and technology. During my summer internship at Jet Propulsion Laboratory I used Adobe Flash and ActionScript 3 to develop content for the Space Place, Climate Kids, and SciJinks sites. In addition, I was involved in the development process for ongoing and new projects during my internship. My involvement allowed me to follow a project from concept to design, implementation, and release. I personally worked on three projects this summer, two of which are currently in deployment. The first is a scrambled letter-tile guessing game titled Solar System Scramble. The second, Butterfrog Mix-Up, is a rotating-tile puzzle game. The third project is a unfinished prototype for a maze game.

video games↗
NASA NTRSDate not supplied

Advances in Modeling Solar System Internet Structures and their Data Flows

With an ever-increasing presence in space, there is also an increasing burden on existing communications infrastructure. We are heading towards an inflection point where the traditional approach of scheduled, single-path communications for space will no longer be viable. One answer is Delay Tolerant Networking (DTN), which takes the once disparate system of point-to-point links and unifies them in a networked architecture, thereby making communications more scalable. However, much work remains for discovering and harnessing the underlying theory of DTN. For example, in the terrestrial setting the interplay between routing domains is well-understood, however this is not the case in DTNs. In this paper, we build up the fundamental foundations of DTN, with an emphasis on modeling time varying networks and data flows across them, with examples of cross-domain routing in a DTN. A lofty goal of DTN is to enable the so-called Solar System Internet (SSI), which implies a standardized and robust suite of protocols. These protocols include routing across disconnected networks using store, carry, and forward mechanisms, which is necessary due to the disconnections, delays, and mobility intrinsic to space networks. Due to these factors, each of which generalize traditional networking, there is a deep and rich theory of DTNs. Here we build off of past successes to broaden this theory while striving to keep actionable results a goal for future implementations and operations. The approach includes modeling the unicast, broadcast, and multicast communications using the language of hypergraphs, which capture the geometric properties of such networked communications algebraically. Also inherent to these networks is their time-varying nature, particularly given mobility, and hence we also cultivate modeling techniques that respect this time dependence. This leads us to develop models using tools from category theory and algebraic geometry, which provide a language well-suited to describing synchronization and optimization over such networks. We also introduce and study a novel generalization of curvature applicable to time-evolving networks, which provides quantitative controls on diffusion processes on the network. Because an interplanetary network would feature links with propagation delays the preclude discovery (feedback) mechanisms, they will always feature a scheduled component. However, it is beneficial to support discovery where possible. While DTNs do not yet have strong definitions for their analogues of autonomous systems or network areas, we show how to join dynamic and schedule-based routing domains, using the language of sheaves, which marks progress towards such definitions. We conclude with a discussion of the progress made, as well as suggestions for future work.

Delay Tolerant Networking↗
NASA NTRS2017

A Multi-Decadal Sample Return Campaign Will Advance Lunar and Solar System Science and Exploration by 2050

There have been 11 missions to the Moon this century, 10 of which have been orbital, from 5 different space agencies. China became the third country to successfully soft-land on the Moon in 2013, and the second to successfully remotely operate a rover on the lunar surface. We now have significant global datasets that, coupled with the 1990s Clementine and Lunar Prospector missions, show that the sample collection is not representative of the lithologies present on the Moon. The M3 data from the Indian Chandrayaan-1 mission have identified lithologies that are not present/under-represented in the sample collection. LRO datasets show that volcanism could be as young as 100 Ma and that significant felsic complexes exist within the lunar crust. A multi-decadal sample return campaign is the next logical step in advancing our understanding of lunar origin and evolution and Solar System processes.

Neal, C. R.↗
NASA NTRS2012

Measuring Isotope Ratios Across the Solar System

Stable isotope ratios in C, H, N, O and S are powerful indicators of a wide variety of planetary geophysical processes that can identify origin, transport, temperature history, radiation exposure, atmospheric escape, environmental habitability and biology [1]. For the Allan Hills 84001 meteorite, for example, the (sup 1)(sup 3)C/(sup 1)(sup 2)C ratio identifies it as a Mars (SNC) meteorite; the ??K/??Ar ratio tells us the last time the rock cooled to solid, namely 4 Gya; isotope ratios in (sup 3)He, (sup 2)(sup 1)Ne and (sup 3)?Ar show it was in space (cosmic ray exposure) for 10-20 million years; (sup 1)?C dating that it sat in Antarctica for 13,000 years before discovery; and clumped isotope analysis of (sup 1)?O(sup 1)(sup 3)C(sup 1)?O in its carbonate that it was formed at 18+/-4 ?C in a near-surface aqueous environment [2]. Solar System Formation

planetary geophysical process↗
NASA NTRS2020

The Inner Solar System's Habitability Through Time

Earth, Mars, and Venus, irradiated by an evolving Sun, have had fascinating but diverging histories of habitability. Although only Earth’s surface is considered to be habitable today, all three planets might have simultaneously been habitable early in their histories to microbial life. We consider how physical processes that have operated similarly or differently on these planets determined the creation and evolution of their atmospheres and surfaces over time. These include the geophysical and geochemical processes that determined the style of their interior dynamics and the presence or absence of a magnetic field; the surface-atmosphere exchange processes that acted as a source or sink for atmospheric mass and composition; the Sun-planet interactions that controlled escape of gases to space; and the atmospheric processes that interacted with these to determine climate and habitability. The divergent evolutions of the three planets provide an invaluable context for thinking about the search for life outside the Solar System.

Anthony D. Del Genio↗
NASA NTRS1988

Lewis Cliff 86010, a unique Antarctic meteorite: Possible new clues to the early history of the solar system

Results form the Antarctic sample, LEW 86010 indicate that it is an extremely interesting meteorite of clear igneous origin, and is probably closely related to ADOR. Several important questions await further detailed study. The most stringent test of the relationship to ADOR will come from the measurement of the oxygen isotopic composition. One possibility proposed is that LEW 86010 represents a partial or total melt of a mixture of material similar to the white Allende clasts and more ordinary chondritic meteorite material. Several lines of investigation will contribute to resolve this question. Further melting studies will be performed to determine whether LEW 86010 represents molten lava. In addition to test the connection with Allende, isotopic studies will look for anomalous isotopic compositions which are ubiquitous in Allende white inclusions. All of these studies will be performed on a tiny sample which weights only 5 grams, and is smaller than a marble, but which contains important clues to events which occurred during the birth of the solar system.

Mckay, G. A.↗
NASA NTRS1992

Secondary electron yields of solar system ices

The secondary electron yields of H2O, CO2, NH3, and CH3OH ices have been measured as a function of electron beam energy in the 2- to 30-keV energy range. The ices were produced on a liquid-nitrogen-cooled cold finger and transferred under vacuum to a SEM where the yield measurements were made. The imaging capabilities of the SEM provide a means of correlating the yield measurements with the morphology of the ices and are also used to monitor charging effects. The yields were determined by measuring the amplified current from a secondary electron detector and calibrating this current signal with the amplified current signal from samples of metals with known secondary electron yields. Each of the measured yields is found to decrease with an increase in energy in the 2- to 30-keV range. Estimates are given for the maximum secondary electron yield Y(max) of each ice and the energy at which this maximum yield occurs. Implications for the charging of solar system ice grains are discussed.

Suszcynsky, David M.↗
NASA NTRS1981

Interplanetary dust in the transmission electron microscope - Diverse materials from the early solar system

An analytical electron microscope study of dispersed interplanetary dust aggregates collected in the earth's stratosphere shows that, in spite of their similarities, the aggregates exhibit significant differences in composition, internal morphology, and mineralogy. Of 11 chondritic particles examined, two consist mostly of a noncrystalline chondritic material with an atomic S/Fe ratio equal to or greater than 2 in places, one consists of submicron metal and reduced silicate 'microchondrules' and sulfide grains embedded in a carbonaceous matrix, and another consists of submicron magnetic-decorated unequilibrated silicate and sulfide grains with thick low-Z coatings. Although the particles are unmetamorphosed by criteria commonly applied for chondritic meteorites, the presence of reduced chemistries and the ubiquity of mafic, instead of hydrated, silicates confirm that they are not simply C1 or C2 chondrite matrix material. The observations indicate that portions of some particles have not been significantly altered by thermal or radiation processes since their assembly, and that the particles probably contain fine debris from diverse processes in the early solar system.

Fraundorf, P.↗
DOE OSTI2020

Determination of Solar System R-Process Abundances using ENDF/B-VIII.0 and TENDL-2015 libraries

Recent multi-messenger detection of the binary neutron star merger (GW170817) energized the astrophysical community and encouraged further research for determination of nuclear physics observables. Comprehensive studies of atomic nuclei in the cosmos provide an opportunity for investigating these astrophysical phenomena and acquiring complementary information on stellar nucleosynthesis processes that can be verified using the latest nuclear data. Evaluated Nuclear Data File (ENDF) libraries contain complete collections of reaction cross sections over the energy range relevant to astrophysics, fission yields and decay data. These data collections have been used worldwide in nuclear science, industry and national security applications. There is great interest in exploring the ENDF/B-VIII.0 and TALYS Evaluated Nuclear Data Library (TENDL-2015) for nuclear astrophysics purposes and comparing findings with the Karlsruhe Astrophysical Database of Nucleosynthesis in Stars (KADoNiS). The Maxwellian-averaged cross sections (MACS) and astrophysical reaction rates have been calculated using the ENDF/B-VIII.0 and TENDL-2015 evaluated data sets. The calculated cross sections were combined with the solar system abundances and fitted using the classical model of stellar nucleosynthesis. Astrophysical rapid- and slow-neutron capture, r- and s-process, respectively, abundances were obtained from present data and compared with available values. Further analysis of MACS reveals potential evaluated libraries data deficiencies and a strong need for new measurements. The current results demonstrate a large nuclear astrophysics potential of evaluated libraries and mutually beneficial relations between nuclear industry and research e orts.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
NASA NTRS2004

Insight into Primordial Solar System Oxygen Reservoirs from Returned Cometary Samples

The recent successful rendezvous of the Stardust spacecraft with comet Wild-2 will be followed by its return of cometary dust to Earth in January 2006. Results from two separate dust impact detectors suggest that the spacecraft collected approximately the nominal fluence of at least 1,000 particles larger than 15 micrometers in size. While constituting only about one microgram total, these samples will be sufficient to answer many outstanding questions about the nature of cometary materials. More than two decades of laboratory studies of stratospherically collected interplanetary dust particles (IDPs) of similar size have established the necessary microparticle handling and analytical techniques necessary to study them. It is likely that some IDPs are in fact derived from comets, although complex orbital histories of individual particles have made these assignments difficult to prove. Analysis of bona fide cometary samples will be essential for answering some fundamental outstanding questions in cosmochemistry, such as (1) the proportion of interstellar and processed materials that comprise comets and (2) whether the Solar System had a O-16-rich reservoir. Abundant silicate stardust grains have recently been discovered in anhydrous IDPs, in far greater abundances (200 5,500 ppm) than those in meteorites (25 ppm). Insight into the more subtle O isotopic variations among chondrites and refractory phases will require significantly higher precision isotopic measurements on micrometer-sized samples than are currently available.

Brownlee, D. E.↗
NASA NTRS1997

Micron-Sized Dust Particles Detected in the Outer Solar System by the Voyager 1 and 2 Plasma Wave Instruments

During the Voyager 1 and 2 flybys of the outer planets it has been demonstrated that the plasma wave instrument can detect small dust particles striking the spacecraft. In this paper, we examine the Voyager plasma wave data for dust impacts in the interplanetary medium at heliocentric radial distances ranging from 6 to 60 astronomical units (AU). The results show that a small but persistent level of dust impacts exists out to at least 30 to 50 AU. The average number density of these particles is about 2 x 10(exp -8)/cu m, and the average mass of the impacting particles is believed to be a few times 10(exp -11) g, which corresponds to particle diameters in the micron range. Possible sources of these particles are planets, moons, asteroids, comets, and the interstellar medium. Of these, comets appear to be the most likely source. The number densities are only weakly dependent on ecliptic latitude, which indicates that the particles probably do not originate from planets, moons, or asteroids. Comparisons with interstellar dust fluxes measured in the inner regions of the solar system by the Ulysses spacecraft indicate that the particles are not of interstellar origin.

Gurnett, D. A.↗
NASA NTRS1997

Micron-Sized Dust Particles Detected in the Outer Solar System by the Voyager 1 and 2 Plasma Wave Instruments

During the Voyager 1 and 2 flybys of the outer planets it has been demonstrated that the plasma wave instrument can detect small dust particles striking the spacecraft. In this paper, we examine the Voyager plasma wave data for dust impacts in the interplanetary medium at heliocentric radial distances ranging from 6 to 60 astronomical units (AU). The results show that a small but persistent level of dust impacts exists out to at least 30 to 50 AU. The average number density of these particles is about 2 x 10(exp -8)/cu m, and the average mass of the impacting particles is believed to be a few times 10(exp -11) g, which corresponds to particle diameters in the micron range. Possible sources of these particles are planets, moons, asteroids, comets, and the interstellar medium. Of these, comets appear to be the most likely source. ne number densities are only weakly dependent on ecliptic latitude, which indicates that the particles probably do not originate from planets, moons, or asteroids. Comparisons with interstellar dust fluxes measured in the inner regions of the solar system by the Ulysses spacecraft indicate that the particles are not of interstellar origin.

Gurnett, D. A.↗