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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.

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All sourcesNASA NTRSDOE OSTI
NASA NTRS1985

Origin of olivine at Copernicus

The central peaks of Copernicus are among the few lunar areas where near-infrared telescopic reflectance spectra indicate extensive exposures of olivine. Other parts of Copernicus crater and ejecta, which were derived from highland units in the upper parts of the target site, contain only low-Ca pyroxene as a mafic mineral. The exposure of compositionally distinct layers including the presence of extensive olivine may result from penetration to an anomalously deep layer of the crust or to the lunar mantle. It is suggested that the Procellarum basin and the younger, superposed Insularum basin have provided access to these normally deep-seated crustal or mantle materials by thinning the upper crustal material early in lunar history. The occurrences of olivine in portions of the compositionally heterogeneous Aristarchus Region, in a related geologic setting, may be due to the same sequence of early events.

Pieters, C. M.↗
NASA NTRS2012

Recent Improvements to the Copernicus Trajectory Design and Optimization System

Copernicus is a software tool for spacecraft trajectory design and optimization. The latest version (v3.0.1) was released in October 2011. It is available at no cost to NASA centers, government contractors, and organizations with a contractual affiliation with NASA. This paper is a brief overview of the recent development history of Copernicus. An overview of the evolution of the software and a discussion of significant new features and improvements is given, and how the tool is used to design spacecraft missions

Williams, Jacob↗
DOE OSTI2012

REVISITING THE CHLORINE ABUNDANCE IN DIFFUSE INTERSTELLAR CLOUDS FROM MEASUREMENTS WITH THE COPERNICUS SATELLITE

We reanalyzed interstellar Cl I and Cl II spectra acquired with the Copernicus satellite. The directions for this study come from those of Crenny and Federman and sample the transition from atomic to molecular-rich clouds where the unique chemistry leading to molecules containing chlorine is initiated. Our profile syntheses relied on up-to-date laboratory oscillator strengths and component structures derived from published high-resolution measurements of K I absorption that were supplemented with Ca II and Na I D results. We obtain self-consistent results for the Cl I lines at 1088, 1097, and 1347 A from which precise column densities are derived. The improved set of results reveals clearer correspondences with H{sub 2} and total hydrogen column densities. These linear relationships arise from rapid conversion of Cl{sup +} to Cl{sup 0} in regions where H{sub 2} is present.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2024

Global anthropogenic emissions (CAMS-GLOB-ANT) for the Copernicus Atmosphere Monitoring Service simulations of air quality forecasts and reanalyses

Anthropogenic emissions are the result of many different economic sectors, including transportation, power generation, industrial, residential and commercial activities, waste treatment and agricultural practices. Air quality models are used to forecast the atmospheric composition, analyze observations and reconstruct the chemical composition of the atmosphere during the previous decades. In order to drive these models, gridded emissions of all compounds need to be provided. This paper describes a new global inventory of emissions called CAMS-GLOB-ANT, developed as part of the Copernicus Atmosphere Monitoring Service (CAMS; https://doi.org/10.24380/eets-qd81, Soulie et al., 2023). The inventory provides monthly averages of the global emissions of 36 compounds, including the main air pollutants and greenhouse gases, at a spatial resolution of 0.1° × 0.1° in latitude and longitude, for 17 emission sectors. The methodology to generate the emissions for the 2000–2023 period is explained, and the datasets are analyzed and compared with publicly available global and regional inventories for selected world regions. Depending on the species and regions, good agreements as well as significant differences are highlighted, which can be further explained through an analysis of different sectors as shown in the figures in the Supplement.

54 ENVIRONMENTAL SCIENCES↗
NASA NTRS1973

Lunar crater Copernicus - Search for debris of impacting body at Apollo 12 site.

In an attempt to characterize meteoritic material at the Apollo 12 site, 4 KREEP concentrates from soil 12033 have been analyzed by neutron activation analysis. These contain a meteoritic component in which siderophile Ir, Re, and Sb are depleted by about a factor of 2, while volatile Se, Zn, Ag, and Bi are depleted by a factor of more than 5 relative to Au. This pattern does not closely resemble any major chondrite or iron meteorite group, but is very similar to that observed in high-alkali samples from Apollo 14. The meteoritic component in KREEP at both sites is therefore predominantly derived from Imbrian ejecta. However, a second, small component of primitive composition seems to be present in Apollo 12 KREEP, judging from the slight, uniform enrichments in Ir, Re, Sb, and Zn relative to Au. This component does not seem to be due to micrometeorites. If it is attributed to the Copernican projectile, the crater Copernicus may have been formed by a cometary nucleus, 4 km in diameter, with an impact velocity of 30 to 40 km/sec. These conclusions depend critically on the assumption that the meteoritic component in Apollo 12 KREEP is representative of the entire impact.

Morgan, J. W.↗
NASA NTRS1973

Spectrophotometric results from the Copernicus satellite. I - Instrumentation and performance.

The Princeton telescope-spectrometer on the OAO spacecraft Copernicus scans stellar spectra with a resolution of about 0.05 A between 950 and 1450 A, and twice this in first order between 1650 and 3000 A. The pointing during several minutes is steady within .02 sec, and the measured photometric precision in the shorter wavelength range is limited only by the statistics of photon counts, with 14-sec counts of about 1000 on an unreddened B1 star, m(v) = 5.0, at 1100 A. In the 1650-3000 A wavelength range, phototube noise resulting from cosmic rays makes observations difficult on stars fainter than m(v) = 3.0.

Rogerson, J. B.↗
NASA NTRS1974

The particle background observed by the X-ray detectors onboard Copernicus

The design and characteristics of low energy detectors on the Copernicus satellite are described. The functions of the sensors in obtaining data on the particle background. The procedure for processing the data obtained by the satellite is examined. The most significant positive deviations are caused by known weak X-ray sources in the field of view. In addition to small systemic effects, occasional random effects where the count rate increases suddenly and decreases within a few frames are analyzed.

Davison, P. J. N.↗
NASA NTRS1975

Copernicus observations of interstellar absorption at Lyman alpha

Column densities NH of atomic hydrogen have been derived for 40 OB stars from spectral scans at Lyman alpha obtained by the Copernicus (OAO-3) satellite. The stars are all between 60 and 1100 pc away with a range of mean densities n sub H of 0.01 to 2.5 atoms cm-3. The gas to color-excess ratio in clouds varies from 1 to 3 times the mean outside of clouds. The presence of molecular hydrogen correlates with E(B-V), but the best tracer for H2 is atomic hydrogen. The mean density of the gas for all 40 stars is much smaller than the mean of 0.7 atoms cm-3 obtained from 21-cm observations, because the brightest stars with less than average amounts of matter in the line of sight were selected for observation.

Bohlin, R. C.↗
NASA NTRS1975

Copernicus observations of Betelgeuse and Antares

Copernicus observations of the M-supergiants, alpha Ori and alpha Sco, are presented. The MgII h and k resonance lines are strongly in emission in both stars. The k line is highly asymmetric in both stars but the h line is symmetric. Upper limits for several other resonance lines are given for alpha Ori. The possibility is explored that the k line asymmetry is caused by overlying resonance lines of MnI and FeI formed in the cool circumstellar gas shells around these stars. Observations of the MnI 4030-4033 A lines are used to show that circumstellar shell absorption is too weak to explain the asymmetry. It is suggested that the absorption occurs in a cool turbulent region between the base of the circumstellar shell and the top of the chromosphere.

Bernat, A. P.↗
NASA NTRS1974

A survey with Copernicus of interstellar O VI absorption

The presence of broad, shallow absorptions caused by O VI ions were revealed from UV spectra observations recorded by the Copernicus satellite for thirty-two stars. A table lists survey data on the stars observed for which values of the O VI column densities or their upper limits are extracted. Interstellar rather than circumstellar origin is evident from observation of the lack of correspondence between radical velocities of the stars and those of the O VI profiles. The presence of a low-density high-temperature phase of interstellar gas produced by supernova explosions is suggested.

Jenkins, E. B.↗
NASA NTRS1974

Highly ionized atoms observed with Copernicus

Based on high-resolution observations using the Princeton satellite/spectrometer on Copernicus the O VI doublet is discussed in detail, in conjunction with data for the resonance lines of N V, Si IV, and S IV reported in five stars. The temperature, density, and the possible extent of the O VI producing region are discussed. The ratio N(S IV)/N(O VI) is used to derive a lower limit to the temperature in the O VI producing region. In near pressure equilibrium with normal interstellar clouds and H II regions minimum densities are found to be consistent with a hot plasma.

York, D. G.↗
NASA NTRS1975

Soft X-ray observations of Centaurus X-3 from Copernicus

We have detected soft X-ray emission from Centaurus X-3 in the 0.6-1.9 keV band, using the focusing telescope aboard OAO Copernicus. The flux is compatible with an extrapolation of the harder X-ray spectrum, attenuated by (3-4) times 10 to the 22nd atoms per sq cm of interstellar and/or circumstellar matter. The data are consistent with the distance estimate of 5-10 kpc derived from the spectroscopic modulus of the optical component, and obviate the need to postulate the primary to be an anomalously subluminous hot star. There is currently no compelling evidence that such models must be invoked to explain any of the observed compact X-ray sources.

Margon, B.↗
NASA NTRS1975

Observations of the interstellar gas with the Copernicus satellite

Results are reviewed for Copernicus far-UV measurements of the absorption lines of H I, D I, H2, and heavier elements in the interstellar gas. Column densities along several lines of sight, as estimated from Ly-alpha absorption-line profiles, confirm that wide differences in the gas density are present in various directions. The measurement of interstellar D I implies an open universe unless alternate sources for this nuclide are found. Analysis of reddened stars for which the line of sight passes through one or more interstellar clouds indicates a depletion of several heavy elements in the gas. It is suggested that the depleted elements may be present in grains rather than molecules and that the intercloud medium may consist primarily of H II with a few small H I clouds.

Morton, D. C.↗
NASA NTRS1975

Ultraviolet observations of alpha Aurigae from Copernicus

Emission lines of L-alpha (1215.67 A) and O VI (1031.94 A) were detected in the spectroscopic binary alpha Aur (Capella) with the Princeton experiment on Copernicus. Temperatures of the emitting regions are inferred to be in excess of 300,000 K. The temperature and emission measure are consistent with a variable source of soft X-rays. If the emission is attributed to the primary star (G5 III), the atmosphere is expanding with velocities of about 20-100 km/s. Such expansion can lead to material within the binary system. The density of interstellar hydrogen inferred from absorption of stellar L-alpha appears to be approximately 0.01 hydrogen atoms per cu cm.

Dupree, A. K.↗